Page  501 ï~~COMPUTER MUSIC PROJECT OF THE UNIVERSITY OF ILLINOIS EXPERIMENTAL MUSIC STUDIOS James W. Beauchamp and Sever Tipei Computer Music Project of the University of Illinois Experimental Music Studios The Computer Music Project is a facility for composition and related research as well as for teaching. Founded in 1984, CMP is now under the umbrella of the Experimental Music Studios established by Lejaren Hiller in 1958. The merge was done in order to facilitate a more uniform approach to the teaching and practice of music and technology as well as to the research related to it. CMP's physical space was reorganized having in mind an efficient, conducive and easthetically pleasing environment. Hardware Configuration The Computer Music Project has a number of multi-user/multi-tasking workstation computers: two NeXTCube computers with optical disk drives, two NeXTStation computers, and one IBM RS-6000 computer. In addition, there is an Intel 386SX single-user computer which is dedicated to music notation output. There are two playback systems each consisting of a mixer, CD player, analog cassette deck, power amplifier, and a pair of loudspeakers. In the room containing four NeXTs there is also an open reel stereo tape recorder and a DAT recorder. The DAT recorder is connected via AES/EBU to a digital interface with one of the NeXTs, a Singular Solutions A/D64x. All computers are networked together, with the UIUC campus network, and with the international Internet. Software Configuration Except for the Intel386SX computer which uses the DOS operating system, all CMP computers use a form of the Unix operating system. The NeXT computers are currently running NeXTStep 2.1 with Mach Unix and the RS-6000 is running X Windows under AIX 3.1. The principal programming languages are C, FORTRAN and Objective C. Programs which deal with disk-stored sound files are preferred to the use of the NeXT's DSP. The most popular public domain programs are rt, a NeXTStep mixing program from Princeton University and CMix and CSound. However, most users in the Computer Music Project write their own programs to generate scores and sound samples or use the Music 4C language, which was developed in CMP and is taught in the computer music course sequence. Original and Specific Projects SOUND SYNTHESIS: MUSIC 4C. This is an enhanced version of Music 4BF, originally developed at Princeton University. Music 4C (M4C) is coded in C for Unix computers. Instruments are referred to in the score by name. The score consists of a series of I statements for specifying note parameters and F cards for specifying stored functions.The result is a sound file which is played back when the execution is completed. DIGITAL INSTRUMENT for ADDITIVE SYNTHESIS on SUPERCOMPUTERS (DIASS), is a M4C instrument for additive synthesis. it allows a very large number of partials for each timbre as well as minute control over their behavior. Partials can be exactly tuned or may form an inharmonic spectrum; ICMC Proceedings 1994 501 Education, Studio Reports

Page  502 ï~~during the duration of the sound a movement between these two alternatives may occur: out of tune overtones focusing and forming a timbre or a well defined timbre being decomposed into individual sine waves. Due to the very large number of controls and inputs, a SCORE WRITER is necessary to facilitate the handling of the instrument. MATCHING SYNTHESIS OF MUSICAL INSTRUMENT SOUNDS. Andrew Homer (Hong Kong University of Science and Technology) and James Beauchamp have collaborated on a project to find efficient models for synthesis of musical instrument tones using techniques for matching synthesized results with the signals produced by original instruments. Models which have been used successfully are multiplecarrier FM, multiple-wavetable, extended nonlinear/filter, and spectral envelope synthesis. An important goal is to identify spectrally-related parameters which have a strong correlation to timbral perception and which operate appropriately over wide ranges of pitch and amplitude. COMPUTER-ASSISTED COMPOSITION USING MP1. MPI has a stochastic layer whose output could be further structured through logical filters (sieves) and patterns (Markov chains). Since all decisions ultimately depend on a set of random numbers, multiple variants of the same piece can be produced by changing the seed for the random number generator. A Manifold Composition is a collection of such multiple realizations of the same data, using the same program (MP1). AUTOMATIC MUSIC PRINTING: the GrafChord interface between MP1 and SCORE. GrafChord reads in an ascii file containing the description of sounds in a composition produced with MP1 or other composition programs and its output is also an ascii file containing instructions for the music printing/editing program SCORE.. SOUND ANALYSIS: SNDAN. Sndan is a package of command line programs for time-variant spectrum analysis, parameter graphics, parameter modification, and resynthesis of.musical sounds. It can be used for timbre research, synthesis model development, or for construction of musical compositions. Music 4C will run with minor modifications on any Unix computer. Sndan with graphics has been successfully installed on NeXT and Silicon Graphics computers. MP1, GrafChord and DIASS are implemented on the IBM RS-6000, on the Cray Y-MP of the National Center for Supercomputing Applications and on the IBM SP1 parallel computer of the Argonne National Laboratory. Public Activity The Computer Music Project periodically organizes concerts of computer-generated tapes with and without live performers which were produced either at the University of Illinois or other computer music centers. CMP guest composers and researchers involved in computer music are often invited to make presentations at the Monday Night Composers Forums sponsored by the Composition-Theory division of the School of Music. Teaching The contribution of CMP student users is significant in both the designing of new software and compositional output. A number of courses prepare the students to become active in the research field. besides more traditional topics such as Musical Acoustics, Computer Sound Synthesis and Computerassisted Composition, the School of Music offers courses in Music Formalization and a seminar in Musical Applications On Supercomputers (in connection with the NCSA's Education Program) Education, Studio Reports 502 ICMC Proceedings 1994