4Ced is a control software for the 4C, a digital signal processor designed by Giuseppe Di Giugno at Ircam. 4Ced was developed by Curtis Abbott towards the end of the seventies.

Brief History – 4Ced is a software designed for the control of the 4C digital signal processor, part of a more complex system dedicated to computer music. It was developed by Curtis Abbott in 1978 at Ircam.

Technical Features – 4Ced has been structured in two main section: the first, essentially a compiler for text file with computer commands. The second, was designed to translate the previous text files in control commands for the 4C processor. The compiler was programmed in Pascal, while this last with the PDP-11 assembler. Many sophisticated levels characterized this software, so to respond to all needs of composers. 4Ced, actually, allowed users to control the digital processor with a great detail, and so you can compose music with a certain freedom.

Differences between the Syn4B – Certainly the previous model to which Curtis Abbott refers was the Syn4B, in turn designed for the control of the 4B processor. Among them, there were many differences. First, the Syn4B was designed for a different computer, the DEC LSI-11, but most important, the Syn4B was not equipped with ADC converters, and so it was impossible import external audio files for real time processing.[1]

Music N’s legacy – However, even the Syn4B was made to offer to composers or musicians, a flexible electronic instrument, able to perform many functions. The Music N programming languages, with their Units Generators, in a modular logic system, representing the reference model even for the Syn4B, that was designed for a digital processor which in turn based on a modular logic.[2] We must remember that Abbott, at Ircam, had available the Music V and the Music 10, two of the most important versions of Music N. Connections among them were rather clear, insomuch as Curtis Abbott declared that learn how to use the Music V or Music 10 would help to use even the 4Ced. We also remember that even the 4Ced was based on alphanumeric text files, as the Music N programming languages, by which to carry algorithms, scores or control procedures for the processor.[2]

Score – The definition of musical events (allocated in the Score section) stress the link between the 4Ced and the Music V. With his control software, Curtis Abbott design two different approaches to music composition: the first obtained by Music N (that is a sequential list of events, with parameters such as duration, frequency, amplitude and others, all combined with specific synthesis algorithms), the second based simply on arithmetic expressions that give back a more exact and expressive control on the digital processor. Benché entrambe le modalità fossero considerate efficaci, la seconda era concettualmente e tecnicamente più complessa ma, del resto, anche più sofisticata dal punto di vista del compositore, visto che consentiva di poter avviare, simultaneamente e in tempo reale, più azioni sul processore 4C.[2]

Command Language – From a certain point of view, 4Ced was a really developing environment dedicated to the 4C digital signal processor. For this, Curtis Abbott has focused his attention on the relation between the software and the user. So, the researcher achieved the Command Language: an interface for a simplified use of the 4Ced, then the 4C.

RTSKED – 4Ced has contributed to develop one of the first computer system for musical composition; with a great flexibility but without compromising the computational speed. Though it was destined to a rapid obsolescence, together with his digital processor, 4Ced had a great importance on the subsequent developing stages of computer music. In fact, it was very important, for example, for developing Max/Msp.[3] Even Max Mathews, the father of the computer music, has much appreciated it, so that he look at the 4Ced to developing RTSKED; a control language for the Crumar General Development System synthesizer.[4] RTSKED, in turn, was a reference point for Miller Puckette and his Max/Msp.

Sequential Drum – But Max Mathews was not inspired by 4Ced only for RTSKED, even the Sequential Drum, a special external controller for the 4C, was closely related to the software of Curtis Abbott. [5]



[1] Gerald Bennett, Research at Ircam in 1978, Rapports IRCAM 1/78, Centre Georges Pompidou, Parigi, 1978.
[2] Curtis Abbott, The 4CED Program in The Music Machine: Selected Readings from Computer Music Journal, Edited by Curtis Roads, The MIT Press, 1989.
[3] Curtis Roads, Interview with Max Mathews, Computer Music Journal, Vol. 4 [4], 1980.
[4] Max Mathews, Joseph Pasquale, RTSKED, a Scheduled Performance Language for the Crumar General Development System, Proceedings of International Computer Music Conference, San Francisco, 1981.
[5] Max Mathews, Curtis Abbott, The Sequential Drum, Computer Music Journal, Vol. 4 [4], 1980.