A system for interactive encoding of music scores under computer control

Abstract

The high-speed digital computer has provided the musician with a powerful tool for music research. In information retrieval, analysis, digital sound synthesis, and music printing, studies have clearly demonstrated the computer's potential for assisting the musician.' At the same time, however, the difficulty of preparing music data for computer processing has been, and continues to be, a major deterrent to large-scale computer-aided music studies. At present, notwithstanding several experiments in which special optical devices have been used in the encoding process,2 the only generally available device for converting music scores to computer-usable code is the keypunch machine. But the keypunch is an awkward device for encoding music: its character set is not compatible with music symbols; it is tedious to use; and proofreading of encoded materials is cumbersome and timeconsuming, even for those whose computer installations provide on-line text editing. As an alternative to both optical encoding, which is highly desirable but developed for only the simplest encoding tasks, and the keypunch machine, which is available but generally unappealing to the musician, we are developing an encoding system at Indiana University that consists of two independent but related encoding devices: a sonic digitizer and an organ keyboard, both attached to the computer, which permit the operator to enter data directly from the score for automatic conversion into computer-usable code without initmate knowledge of the code itself or the cumbersome proofreading normally associated with keypunching. Once data are encoded, the programs output the code into standard card-image format for storage on magnetic tape. This feature allows a tape to be processed at any computer installation capable of handling magnetic tape. For portability, all programs are written in ANSI standard FORTRAN to allow operation on any computer with a FORTRAN compiler and appropriate encoding devices and display equipment. The encoding language, the MUSTRAN code originated by Jerome Wenker,3 was chosen for several reasons. First, MUSTRAN is a largely mnemonic code and is relatively complete. Second, it has an operational translator and syntax analyzer that we have running on our CDC 6600 computer on campus. (Versions are also available for IBM and UNIVAC machines.) Third, Wenker having recently updated his language and its associated translator and syntax analyzer (called MUSTRAN II), the language is maintained and current. And fourth, our Computer Music System (discussed briefly below) uses MUSTRAN for encoding, music printing, and analysis. At the same time, however, we realize that the DARMS (Ford-Columbia) language is also carefully designed. It recently has been written in canonical form4 and will no doubt eventually have its own translator and syntax analyzer. Since DARMS is a complete language, and in view of the current efforts being made in its behalf, we are now developing DARMS-toMUSTRAN and MUSTRAN-to-DARMS conve sion packages that will eventually allow us to encode in one language and conveniently convert