Music 4C is a sound synthesis software developed in C language. It belongs to the so-called Music N family of programming language for computer music.
Background history – In the line of descent of the Music N computer music language, Music 4C appears linked to Music IV more than others. It should be noted, however, that this is not a direct descent, because it is mediated by software such as Music IVB and Music IVBF. The letter C, as in Cmusic, Cmix and Csound, focuses on the change of programming language compared with previous software. Music 4C was developed in 1985 by James Beauchamp and Scott Aurenz at the University of Illinois.
Features – As part of the Music N, we find in this software the main features of the whole family: use of unit generators, algorithms construction based on alpha-numeric approach and a section called score understood as a series of sound events, each of which equipped with a set of values that define various parameters such as frequency, duration, etc. Music 4C, even in those years, was distributed with the source code, allowing anyone to customize the program. This was also distributed along with a small library of tools already filled and ready for use, a utility which could use less experienced users to experiment with musical composition immediately through the computer.
Portability – being developed for Unix systems only, Music 4C did not present itself as a very versatile software. In the following years Beauchamp has never updated their program to other operating systems, Windows or Mac, and therefore soon fell into disuse.
For this topic I’ve read:
 James Beauchamp, Music 4C, a Multi-Voiced Synthesis Program with Instrument Defined in C, Journal of Acoustical Society of America, Vol. 113, N°. 4, 2003.