The Archiving of Obsessed Again… by Keith Hamel
InterPARES 2, Case Study Report 13
by Scott Amort, Keith Hamel, Jesse Read, John Roeder and David Litke
This article was originally prepared as a final report (February 2004, rev. 2006, 2008) for a Case Study that was part of the second phase of the InterPARES project. The original report has been restructured and some sections removed in view of publication in eContact! 10.x: a Glossary of Terms has not been included, as it is assumed that the reader is familiar with electroacoustics; a number of diagrammes describing methodology models undertaken in the context of the project have been omitted; a section proposing a manner of documenting interaction of the acoustic and electroacoustic elements has been left out. The full report is available here for those wishing to consult these details.
Towards a Strategy for the Preservation of Electroacoustic Music
Methodology and Context
Core Research Questions: Interview with the composer
Research Questions Concerning Policies to Assure Authenticity
Notes and Bibliography | InterPARES
Obsessed Again… is a work for bassoon and interactive electronics by Canadian composer Keith Hamel. The first version of the work was composed in 1992 to fulfil a commission from bassoonist Jesse Read, who requested a piece involving interactive electroacoustic elements, and was premiered on May 9, 1992, at De IJsbreker, Amsterdam, the Netherlands. The work realized these interactive elements by utilizing the Max music software environment along with a commercial Proteus 1 synthesizer and an IVL pitch-to-MIDI converter. Although the composition was designed to use state-of-the-art commercial hardware and software, the equipment required to perform Obsessed Again… is quickly becoming obsolete — the computer files are incompatible with current operating systems and some are stored on older single-sided computer disks, and much of the hardware used is ageing and will soon be inoperable. The work has not been performed for several years, but Dr. Read has expressed a desire to reintroduce it into his repertoire in a form that can be performed easily using current technology (both hardware and software). To meet this requirement, the composition will require recovery and a substantial reworking of both the interactive and electronic elements. In addition, migration strategies will be investigated so that the current scenario does not repeat itself. However, before any such attempts are undertaken, it is necessary to identify and determine the current state of the component elements of Obsessed Again…
Electroacoustic music, that is, music written strictly for performance through electronic means, presents a variety of challenges for the archivist. Unlike traditional acoustic music where various physical records are created by the composer during the composition process — such as sketches and the musical score, for example — electroacoustic composition often only leaves digital entities behind for the archivist. Aside from a recording, possibly itself in digital format (e.g., wave, mp3, etc.), these digital entities are left in a proprietary software format that is generally usable only by a specific software program. Although an instrument such as the violin will most likely be available for future musicians (in more or less the same state available to musicians today), the digital and electronic components that are utilized for a particular electroacoustic composition are almost guaranteed to be obsolete within a very short time period after the work’s creation. The technology employed by composers over the last half-a-century has progressed dramatically, and both hardware and software components are routinely discarded for newer, faster solutions.
Towards a Strategy
Obsessed Again… has provided an excellent case study from which to develop strategies for digital music preservation. The electronic components for this work include a variety of software components, plus two major hardware requirements. It is the latter that demonstrates the most obvious preservation problem. A hardware sound synthesizer (the Proteus) and a hardware pitch-to-MIDI converter are essential to the original conception of the piece. However, they are now technologically obsolete, and the units in the possession of Dr. Keith Hamel (the composer) are very much in danger of ceasing to function.
Currently, the clearest course for the future recreation and study of this work is to model the hardware requirements in the software realm. The specific sounds made by the Proteus synthesizer can relatively easily be copied and stored as a digital object. The most obvious form for this digital entity is currently a Max/MSP (Max) patch. Max is the software used to govern the interaction between the bassoonist and the electronic instrument during performances. When Obsessed Again… was originally composed, Max did not possess a digital sound processing component (the MSP portion); it has since developed strong capabilities in this area, however. It is also possible to model the pitch-to-MIDI converter. In fact, several alternatives are freely available as Max software patches (i.e., components). The main drawback of this, however, is that while functional, these patches lack the reliability and accuracy of the hardware model. It is likely, however, that this will improve with time.
Work has been undertaken to begin this process. Unfortunately, this approach has not solved the primary issue of digital preservation. While it has aided in consolidating the data (i.e., placing all digital components of the work into a common format and location), the format of this digital entity is still dependent on a commercial software application. While it is possible to save Max files as plain text (which will then place the preservation mechanism into the same arena as a standard word-processing file), the Max application itself is still necessary for a successful performance of the piece. Dr. Hamel has since further explored other data encapsulation possibilities by engineering the ability to embed Max control data into his music notation software program (NoteAbility Pro), but this still leaves the data in a proprietary format, albeit in one controlled by the composer.
Notation of Electroacoustic Music
The next necessary step in developing a lasting preservation strategy is to remove all software dependence and develop a descriptive/representational language for electroacoustic music. While a format for this language is still unknown, various projects are currently at work describing conventional music notation (e.g., the GUIDO Music Notation Project), and it may be possible to extend or integrate an electro- acoustic description into these attempts. As of the writing of this report, a first step towards describing the interaction of the acoustic and electroacoustic elements of Obsessed Again… has taken place. The results of this attempt can be viewed at the end of the full report (see PDF, pp. 34–44).
However, one major caveat must accompany these attempts: this sort of descriptive record creation will in no way result in an historically accurate re-creation of the work. Only the intent of the composer will be recorded. It will be almost guaranteed that a future performance based on these descriptions will result in an acoustically-unique piece that may share very little sound material with the original. Nonetheless, the basic structure and interactions of the work will be intact. The implications of this result will most assuredly need to be examined in great detail, but it is worth noting that for the particular case of Obsessed Again…, Keith Hamel fully expects and welcomes this re-composing.
The primary information gathering activity for this case study was a series of interviews with the composer, Keith Hamel and performer, Jesse Read. The interviews were designed to obtain enough information from each interview subject to answer twenty-three core questions (see Sections D and E for the specific questions and their answers).
The composition Obsessed Again… is represented by a musical score, which notates and provides instructions governing the interaction of all of the elements making up the piece — the performer/bassoonist, a Barkus Berry pick-up (microphone), an IVL pitch-to-MIDI converter, a Macintosh computer with a MIDI interface running the Max software, an external Proteus 1 synthesizer and a sound amplification system (i.e., amplifier, mixer and speakers). By accurately following the score, the sonic entity that is the musical work will be produced. Achieving this sonic event will involve two creative processes: the composition of the musical work (i.e., the preparation of the score) and the performance (i.e., the act of realizing the musical work through an accurate interpretation of the score).
The primary individual responsible for the creation of Obsessed Again… is the composer, Keith Hamel. He is the sole creator of the musical work. However, as performer, Jesse Read plays an essential role in contributing to the dissemination of this work and is also responsible for additional entity creation (i.e., recordings). Additionally, Dr. Read collaborated with Dr. Hamel during the compositional process, testing many aspects of the work. Dr. Read considers his role as one of an “interpreter” of Dr. Hamel’s musical work. Also of importance is that by virtue of being the commissioning agent, Dr. Read did provide the initial impetus for the creation of this work and dictated the basic framework within which Dr. Hamel would create Obsessed Again… (i.e., a specification for a musical work for solo bassoon involving the use of interactive electronics).
There are no specific or extraordinary regulations or laws that affect musical composition. Of interest, though, is the use of Copyright law as the main legal instrument of authenticity and ownership.
No generally accepted or documented procedural rules or schemes exist for entities created through musical composition and performance.
The documentation process is chiefly the responsibility of the composer, in whose fonds the composition still resides, and as with the procedural element above, there are no generally accepted rules or schemes.
The original digital environment used for the creation of Obsessed Again… was an Apple Mac II computer (68020), running Mac OS 7. However, this environment has been updated to an Apple PowerBook laptop computer (G4), running Mac OS X 10.3.2. As well, the initial Max software (version 2), has been upgraded to Max/MSP (version 4.2). Additionally, a NeXT computer was used for additional file storage and backups. Although initial compositional work for Obsessed Again… occurred away from a digital environment (involving basic sketches of overall form and determination of pitch material and rhythmic aspects for the bassoon part), most of the remaining work occurred at the computer. The Proteus 1 synthesizer was also used as a test platform, simulating the MIDI input provided by the IVL converter. This allowed Dr. Hamel to construct and test many of the interactive elements without requiring a bassoonist to be present.
1. What activities of the creator have you investigated?
This study examined the compositional process utilized to create Obsessed Again…, and the procedures that Keith Hamel uses to maintain the elements comprising his musical work. As well, an additional party (a performer, in this case Jesse Read) is required to fully realize the sonic event that is the end result of the compositional process. The role of the performer has also been investigated, as it contributes to the creative process.
2. Which of these activities generate the digital entities that are the objects of your case study?
The compositional process can be considered an ongoing event, directly involving the act of maintaining and updating the musical work and component elements. This overall process generates the main digital entities being examined. Additionally, Obsessed Again… is disseminated by way of performance, and this act may also generate digital entities.
3. For what purpose(s) are the digital entities you have examined created?
There are two purposes for the digital entities comprising Obsessed Again…:
- to provide the necessary data and instructions with which a performer can (re)produce a performance of the musical work; and
- to provide a framework allowing the composer to continue the compositional process as deemed necessary (i.e., updates, revisions, etc.).
4. What form do these digital entities take? What are the key formal elements, attributes, and behaviour (if any) of the digital entities?
Dr. Hamel maintains three digital entities, all contained on his Apple PowerBook computer:
- a representation of the musical score — NoteWriter music notation software computer files (bassoon part, bassoon part along with information about the electronic part, graphic images used in the scores). Additionally, these files have been converted to postscript format for backup storage;
- the software patch for Max/MSP, which contains a digital description of the computer “instrument” (master patch file, which will load all other required Max/MSP elements) and additional MIDI sequencer data (15 MIDI files containing musical data sent to the Proteus synthesizer); and
- the Proteus Editor/Librarian file, which describes the voices (sounds) to be used by the Proteus 1 synthesizer.
4b. What are the digital components of which they consist and their specifications?
The format of each digital entity is dictated by the specifications of the individual software programs with which each file was created. The NoteWriter (.nwr), Max/MSP and Editor/Librarian files are proprietary, binary formats, and as such, their specifications are unreleased. The MIDI files used by the Max/MSP patches are standard text files following the MIDI specification.
4c. What is the relationship between the intellectual aspects and the technical components?
The main intellectual aspect of Obsessed Again… (the interaction of bassoon and electronics) is completely realized and documented by the technical components.
4d. How are the digital entities identified (e.g., Is there a [persistent] unique identifier?
Each of these digital entities is identified through the assignment of a semi-descriptive filename.
4e. In the organization of the digital entities, what kind of aggregation levels exist, if any?
As described above, two aggregation levels exist:
- the digital score entities; and
- the digital entities necessary to provide the electronic interaction.
4f. What determines the way in which the digital entities are organized?
The organization method is at the sole discretion of Keith Hamel.
5. How are those digital entities created?
Each digital entity was created/maintained through the use of a commercial computer software program. The original 1992 version of Obsessed Again… utilized Max version 2.0 (for the Max patches), Performer version 5.5 (for creating the MIDI sequences and saving them as standard MIDI files), NoteWriter (for the score) and version 1.0 of the Galaxy Editor/Librarian (for the Proteus Editor/Librarian file). Recently, Dr. Hamel has updated many of the digital entities in preparation for recreating this piece. Newer software includes Max/MSP version 4.2 and NoteAbility (a replacement for NoteWriter).
5a. What is the nature of the system(s) with which they are created? (e.g., functionality, software, hardware, peripherals, etc.)
As it is possible to consider two distinct but related creative processes (creation of the musical work, and creation of the performance), there are also two creative systems. For the creation of the musical work and its digital elements, the original digital system used was an Apple Mac II computer (68020), running Mac OS 7 (as mentioned above, this environment has recently been updated to an Apple PowerBook laptop computer [G4], running Mac OS X 10.3.2). Additionally, a NeXT computer was used for additional file storage and backups. These computers executed software designed to create each of the necessary digital entities (see above for a list of the software employed).
The system required to actually perform the work consists of:
- a platform running Max/MSP (the generator of the electronic elements) loaded with all of the required patches;
- the Proteus 1 synthesizer which converts the digital MIDI data output from Max/MSP to an analogue sound signal, loaded with the necessary Editor/Librarian patches;
- a microphone to record the sound of the bassoon as an analogue sound signal;
- an IVL pitch-to-MIDI converter to convert the analogue bassoon signal to digital MIDI data for input into Max/MSP; and
- a sound amplification system necessary to output the analogue signal produced by the Proteus synthesizer.
5b. Does the system manage the complete range of digital entities created in the identified activity or activities for the organization (or part of it) in which they operate?
Yes, all operations performed on the digital entities occur within the confines of the above two digital systems.
6. From what precise process(es) or procedure(s), or part thereof, do the digital entities result?
The digital entities are a direct result of the personal compositional process as employed by Keith Hamel. This process is unique to each composition, but can be generally summarized (in the case of Obsessed Again…) as follows:
- pre-compositional ideas were sketched, using pencil and paper away from the computer and included items such as the overall form of the work, the working out of basic pitch and harmonic content and determination of the nature of the interaction between the instrument and electronics;
- working from this initial draft, the interactive elements were created at the computer using the necessary software;
- these interactive elements were then tested (utilizing the Proteus synthesizer as a virtual performer) and modifications to both the draft score and software files were made as necessary; until,
- final versions of the digital entities were created and a final score was prepared in digital format.
7. To what other digital or non-digital entities are they connected in either a conceptual or a technical way? Is such connection documented or captured?
The three digital entities are connected to each of the remaining non-digital elements of Obsessed Again… summarized at the beginning of this section (i.e., the additional hardware necessary to perform the piece). The connection is documented in a general sense through the musical score, although the composer admits that he has not adequately notated the electronic entities involved, and that the score is more focused on the musical elements (i.e., traditional pitches and rhythms) that the bassoonist is required to produce. This was a result of a performer-focused attitude, and the fact that the performer did not need to know the details of these entities to satisfactorily perform the piece. Dr. Read echoes this last sentiment; however, as a performer, he does not feel that a more accurate notation for the electroacoustic entities is necessary.
8. What are the documentary and technological processes or procedures that the creator follows to identify, retrieve, and access the digital entities?
The digital entities are accessed through generally employed computer usage (i.e., files are stored on disk and accessed from within the associated software program), and are identified through the use of semi-descriptive file names.
9. Are those processes and procedures documented? How? In what form?
Although not specifically focused on accessing the digital entities of Obsessed Again…, instruction manuals exist for each of the software programs utilized that describe the general procedures necessary to interact with their digitally stored materials. However, specific information concerning filenames and versions directly employed by Obsessed Again… are available only through communication with Dr. Hamel.
10. What measures does the creator take to ensure the quality, reliability and authenticity of the digital entities and their documentation?
Specific procedures are not in place to ensure these qualities; however, by being the sole possessor of all the digital entities in question, Dr. Hamel is able to maintain what he views as an adequate level of control over the distribution of authentic digital elements to performers or other agencies. No specific procedures would prevent a second-hand distribution (i.e., by the performer or agency to another performer), but a general sense of respect for the composer is usually found in these instances. Dr. Read states that as a performer, he feels a responsibility to the composer to be certain that any further dissemination of the piece occur only as prescribed by Dr. Hamel.
11. Does the creator think that the authenticity of his digital entities is assured, and if so, why?
Dr. Hamel is the sole arbiter of authenticity and the only preserver/distributer of these digital entities, and as such, is confident that they are authentic. However, no specific procedures are in place that would allow a third party to independently confirm this authenticity. Additionally, no technological method (i.e., encryption technique, digital signature, etc.) is employed to prevent a third party from redistributing these digital entities and/or compromising their authenticity. However, the creative work as a whole is copyrighted, and Dr. Hamel feels this is a reasonable deterrent against unauthorized alteration and reproduction.
12. How does the creator use the digital entities under examination?
The digital entities are stored for future dissemination to performers and/or for alteration as judged necessary by Dr. Hamel.
13. How are changes to the digital entities made and recorded?
All alterations are made by the composer himself, and he does not record these changes in any formal manner.
14. Do external users have access to the digital entities in question? If so, how, and what kind of uses do they make of the entities?
External users do not have access to the master copies of the digital entities, as maintained by Dr. Hamel. However, duplicates are made and distributed to potential performers and/or other interested parties (e.g., students, arts organizations, etc.). These distributions may result in a fragmentary dissemination of the work, as certain individual elements (most notably the score) are often the only object duplicated. Of course, the most likely scenario for a distribution would be to allow for a performance of the work.
15. Are there specific job competencies (or responsibilities) with respect to the creation, maintenance, and/or use of the digital entities? If yes, what are they?
Basic technical knowledge of computer hardware, as well as specific proficiency in the software applications involved, is necessary for maintenance and use of the digital entities. Additionally, an adequate musical training and an ethical responsibility and respect for the composer’s work are both necessary for any performance-related interaction and revision.
16. Are the access rights (to objects and/or systems) connected to the job competence of the responsible person? If yes, what are they?
This question is somewhat inapplicable to the current study; however, as stated in the answer to the previous question, a certain level of competence with computer hardware and software, as well as an adequate level of musical training, is required to intelligently access/modify the digital entities. As a result, access is in a sense restricted to persons in possession of these abilities.
17. Among its digital entities, which ones does the creator consider to be records and why?
Dr. Hamel does not consider any of these entities to be records. As a composer, he is focused more on the present use of a work, not its past or future states. Many works have only a short-term existence, and this is most evident with those involving technology. Limitations of current software and hardware, and the speed of advances in capabilities are the most limiting factors. All of the digital entities for Obsessed Again… are treated in a utilitarian, not archival, sense.
18. Does the creator keep the digital entities that are currently being examined? That is, are these digital entities part of a recordkeeping system? If so, what are its features?
Although the creator does keep the digital entities in question, there is no formal recordkeeping system employed by Dr. Hamel. The digital entities are stored on computer disks, which remain in the possession of the composer.
18a. Do the recordkeeping system(s) (or processes) routinely capture all digital entities within the scope of the activity it covers?
As answered above, no such system exists, but Dr. Hamel does capture and store all the digital entities he feels are required by the work.
18b. From what applications do the recordkeeping system(s) inherit or capture the digital entities and the related metadata (e.g., email, tracking systems, workflow systems, office systems, databases, etc.)?
18c. Are the digital entities organized in a way that reflects the creation processes? What is the schema, if any, for organizing the digital entities?
The digital entities reflect the creation process in so much as they are organized by file type (i.e., the individual files are dictated by the software program used to create them).
18d. Does the recordkeeping system provide ready access to all relevant digital entities and related metadata?
Again, no system exists, but Dr. Hamel currently has ready access to all relevant digital entities.
18e. Does the recordkeeping system document all actions/transactions that take place in the system re: the digital entities? If so, what are the metadata captured?
No such documentation exists.
19. How does the creator maintain its digital entities through technological change?
Initially, no active actions were taken to protect against technological advance. However, as described in the overview to this report, a recent attempt to reintroduce this work into the active repertoire has forced a re-examination of this decision. As of the writing of this report, Dr. Hamel has translated many of the original entities into forms accessible by current technology. Unfortunately, it does appear as though particular elements — the editor/librarian patch for the Proteus 1, specifically — will be impossible to update due to obsolete software, and as a result will need to be recreated. Additional concerns have been raised with regards to the age of some of the non-digital entities (the aforementioned Proteus 1 and the original Macintosh computer). While these entities can be updated to current hardware versions (or possibly of more benefit to future storage, be converted to a software representation), these changes will alter the nature of the composition (i.e., sound production will change, overall sound quality will differ, etc.), and may also require alteration to connected elements. As a result, the sonic event that is Obsessed Again… will be fundamentally different. It is interesting to note, however, that Dr. Hamel does not view this outcome in a negative manner, and in fact, he is quite pleased to rework elements of his piece. Dr. Hamel sees the process of archiving not as an act of historical preservation, but instead, as a means of ensuring his composition's future existence. This focus will require a more complete musical score with much more detailed indications of the interaction between the acoustic and electroacoustic elements, and the inclusion of a digital recording of an authentic version of the work by which future performances can be judged.
19a. What preservation strategies and/or methods are implemented and how?
The main preservation strategy implemented by Dr. Hamel has been to reduce the hardware dependence of Obsessed Again… and re-implement as many of the interactive elements as possible in software. Currently, the Proteus 1 synthesizer is no longer required, and its sound production procedure has been implemented as a software synthesizer patch in Max/MSP. Dr. Hamel has identified Max/MSP as the current best option for software/hardware amalgamation. Although not currently employed, Max/MSP pitch-to-MIDI converters do exist, which would allow for the additional replacement of the IVL converter.
19b. Are these strategies or methods determined by the type of digital entities (in a technical sense) or by other criteria? If the latter, what criteria?
Yes. Dr. Hamel’s ultimate goal is to remove external hardware dependencies (with the exception of the system necessary to run Max/MSP) and re-implement them as a Max/MSP patch.
20. To what extent do policies, procedures, and standards currently control records creation, maintenance, preservation and use in the context of the creator’s activity? Do these policies, procedures, and standards need to be modified or augmented?
There is currently very little in the way of formalized policies, procedures or standards involved with Obsessed Again… The creation of such elements is seen as a priority for the composer, with respect to both this specific work and as a means to introduce standardized procedures and policies for archiving electroacoustic music as a whole.
21. What legal, moral (e.g., control over artistic expression) or ethical obligations, concerns or issues exist regarding the creation, maintenance, preservation and use of the records in the context of the creator’s activity?
As composer, there is no external moral or legal responsibility concerning the creation, maintenance, preservation and use of the digital entities that comprise Obsessed Again… (1) There is, however, a more internal moral dedication to ensuring the future life of this work.
22. What descriptive or other metadata schema or standards are currently being used in the creation, maintenance, use and preservation of the recordkeeping system or environment being studied?
No such schema or standards are used.
23. What is the source of these descriptive or other metadata schema or standards (institutional convention, professional body, international standard, individual practice, etc.)?
1. What legal or moral obligations exist regarding the creation, maintenance, preservation, and use of the records of artistic and scientific activities?
As discussed above, the composer feels a moral obligation to ensure the future existence of his work, but no real compulsion towards preservation for archival purposes. Legal obligations do exist, focused mainly on copyright and authorship issues (for authenticity verification, performing rights, etc.); however, these do not constitute a pressing concern for Dr. Hamel.
2. What principles should guide the formulation of policies, strategies and standards related to the creation of reliable, accurate and authentic records in the digital environments under investigation?
The main concern for Dr. Hamel is that the future existence of his work be ensured. This principle should guide all policy formulations. Specifically, Dr. Hamel feels that priority should be given to the development of descriptive procedures that can ensure that the creation of the electroacoustic elements of Obsessed Again…, as well as the descriptive documentation of the interaction between performer and computer, results in digital entities that are reliable, accurate and authentic. Combined with existing music notation procedures (which can be described as adequately accurate and authentic), these descriptive procedures would allow for a complete account of the actions necessary to (re)create Obsessed Again…
3. What principles should guide the formulation of policies, strategies and standards related to the appraisal of those records?
As explicitly stated above, the accuracy and authenticity of all digital entities must be assured.
4. What is the relationship between the role of descriptive schemas and instruments needed by the creator and those required by the preserver to support the archival processes of appraisal, preservation and dissemination?
It would seem likely that a means to ensure accuracy and authenticity could be integrated into the descriptive schemas developed as described above in question 2. Separate schemas for the creator and preserver would not be necessary.
5. What is the role of descriptive schemas and instruments in rights management and in identifying and tracking records components, versions, expressions, performances, and other manifestations, and derivative works?
This would be a vital role, as it is an examination of these attributes that will allow for others to ensure the accuracy and authenticity of the work (and its digital components).
6. Is it important to be able to relate the record of artistic and scientific activity to the associated expression, performance, product, work, or other manifestation of it? If so, in what ways can descriptive activities facilitate it?
Yes it is important, however, not necessarily for the creator. Documentation of the processes involved in creating Obsessed Again… may have a historical value to musicologists or others, but for the composer, it is the musical work that must be preserved. For his purposes, all digital entities must ultimately relate to the future (re)creation of this work.
Descriptive facilities are the core means of ensuring the accuracy and authenticity of Obsessed Again… during its (re)creation, and the preservation of its accuracy and authenticity over the long-term. Current efforts at creating a text-based meta-language for digital storage of musical scores can already be seen to facilitate a complete digital description of the musical work. Examples such as GUIDO and MusicXML (see bibliography) are also extensible, allowing for the addition of means to help ensure the accuracy and authenticity of electroacoustic musical works.
- It appears that Obsessed Again… constituted an informal, verbal commission with no legal obligations. Moreover, as noted in question 17, Dr. Hamel does not consider any of the digital entities comprising Obsessed Again… to be records.
Anthony, Don, Charles Cronin and Eleanor Selfridge-Field. “The Electronic Dissemination of Notated Music: An Overview.” The Virtual Score: Representation, Retrieval, Restoration. Edited by W.B. Hewlett and E. Selfridge-Field. Cambridge, MA: MIT Press, 2001, pp. 135–66.
Bari, Andrea, Sergio Canazza, Giovanni De Poli and Gian Antonio Mian. “Toward a Methodology for the Restoration of Electroacoustic Music” Journal of New Music Research 30/4 (December 2001), pp. 351–63.
Canazza, Sergio and Alvise Vidolin. “Introduction: Preserving Electroacoustic Music.” Journal of New Music Research 30/4 (December 2001), pp. 289–93.
Castan, Gerd, Michael Good, and Perry Roland. “Extensible markup language (XML) for music applications: An introduction.” The Virtual Score: Representation, Retrieval, Restoration. Edited by W.B. Hewlett and E. Selfridge-Field. Cambridge, MA: MIT Press, 2001, pp. 95–102.
Chadabe, Joel. “Preserving Performances of Electronic Music.” Journal of New Music Research 30/4 (December 2001), pp. 303–5.
Davies, Hugh. “The Preservation of Electronic Musical Instruments.” Journal of New Music Research 30/4 (December 2001), pp. 295–302.
Hamel, Keith A. “Obsessed Again…” (1992), for Bassoon and Interactive Electronics.
Hoos, Holger, Keith Hamel, Kai Renz and Jürgen Kilian. “Represented Score-Level Music Using the GUIDO Music-Notation Format.” The Virtual Score: Representation, Retrieval, Restoration. Edited by W.B. Hewlett and E. Selfridge-Field. Cambridge, MA: MIT Press, 2001, pp. 75–94.
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