ChucK

Short description: Audio programming language

ChucK

Paradigm	Multi-paradigm
Designed by	Ge Wang
First appeared	2003 (2003)
Stable release	1.5.2.0 / November 2023 (2023-11)
Typing discipline	Strong
OS	Cross-platform
License	Mac, Linux, Windows: GPL-2.0-or-later iOS: Closed Source (Not Public)
Website	chuck.cs.princeton.edu

ChucK is a concurrent, strongly timed audio programming language for real-time synthesis, composition, and performance, which runs on Linux, Mac OS X, Microsoft Windows, and iOS. It is designed to favor readability and flexibility for the programmer over other considerations such as raw performance. It natively supports deterministic concurrency and multiple, simultaneous, dynamic control rates. Another key feature is the ability to live code; adding, removing, and modifying code on the fly, while the program is running, without stopping or restarting. It has a highly precise timing/concurrency model, allowing for arbitrarily fine granularity. It offers composers and researchers a powerful and flexible programming tool for building and experimenting with complex audio synthesis programs, and real-time interactive control.

ChucK was created and chiefly designed by Ge Wang as a graduate student working with Perry R. Cook. ChucK is distributed freely under the terms of the GNU General Public License on Mac OS X, Linux and Microsoft Windows. On iPhone and iPad, ChiP (ChucK for iPhone) is distributed under a limited, closed source license, and is not currently licensed to the public. However, the core team has stated that it would like to explore "ways to open ChiP by creating a beneficial environment for everyone".

Language features

The ChucK programming language is a loosely C-like object-oriented language, with strong static typing.

ChucK is distinguished by the following characteristics:

• Direct support for real-time audio synthesis
• A powerful and simple concurrent programming model
• A unified timing mechanism for multi-rate event and control processing.
• A language syntax that encourages left-to-right syntax and semantics within program statements.
• Precision timing: a strongly timed sample-synchronous timing model.
• Programs are dynamically compiled to ChucK virtual machine bytecode.
• A runtime environment that supports on-the-fly programming.
• The ChucK Operator (=>) that can be used in several ways to "chuck" any ordered flow of data from left to right.

ChucK standard libraries provide:

• MIDI input and output.
• Open Sound Control support.
• HID connectivity.
• Unit generators (UGens) - ie oscillators, envelopes, synthesis toolkit ugens, filters, etc.
• Unit analyzers (UAnae) - blocks that perform analysis functions on audio signals and/or metadata input, and produce metadata analysis results as output - ie FFT/IFFT, Spectral Flux/Centroid, RMS, etc.
• Serial IO capabilities - ie Arduino.
• File IO capabilities.

Code example

The following is a simple ChucK program that generates sound and music:

 // our signal graph (patch)
 SinOsc f => dac;
 // set gain
 .3 => f.gain;
 // an array of pitch classes (in half steps)
 [ 0, 2, 4, 6, 9, 10 ] @=> int hi[];
 
 // infinite loop
 while( true )
 {
     // choose a note, shift registers, convert to frequency
     Std.mtof( 65 + Std.rand2(0,1) * 43 +
         hi[Std.rand2(0,hi.cap()-1)] ) => f.freq;
 
     // advance time by 120 ms
     120::ms => now;
 }

Uses

ChucK has been used in performances by the Princeton Laptop Orchestra (PLOrk) and for developing Smule applications, including their ocarina emulator. PLOrk organizers attribute some of the uniqueness of their performances to the live coding they can perform with ChucK.

See also

• Comparison of audio synthesis environments
• Sonic Pi
• Pure Data

Further reading

Literature by its authors

• Wang, G. (2018). Artful Design: Technology in Search of the Sublime. Stanford University Press. ISBN 978-1503600522. https://artful.design/. 
• Wang, G.; Cook, P.; Salazar, S. (2015). "ChucK: A strongly-timed computer music language". Computer Music Journal. https://ccrma.stanford.edu/~ge/publish/files/2015-cmj-chuck.pdf. 
• Wang, G. (2008). "The ChucK Audio Programming Language". PhD Thesis, Princeton University.. https://ccrma.stanford.edu/~ge/thesis.html. 
• Wang, G; Fiebrink, R; Cook, P (2007). "Combining analysis and synthesis in the ChucK programming language". Proceedings of the International Computer Music Conference. http://soundlab.cs.princeton.edu/publications/uana_icmc2007.pdf. 
• Wang, G; Misra, A.; Kapur, A; Cook, P (2005). "Yeah ChucK it! => Dynamic, controllable, interface mapping". Proceedings of the International Conference on New Interfaces for Musical Expression. http://soundlab.cs.princeton.edu/publications/chuck_nime2005.pdf. 
• Wang, G.; Cook, P.; Misra, A (2005). "Designing and implementing the ChucK programming language". Proceedings of the International Computer Music Conference. http://soundlab.cs.princeton.edu/publications/chuck_icmc2005.pdf. 
• Wang, G.; Cook, P. (2004). "The Audicle: A context-sensitive, on-the-fly audio programming environ/mentality". In Proceedings of the International Computer Music Conference. http://soundlab.cs.princeton.edu/publications/audicle_icmc2004.pdf. 
• Wang, G.; Cook, P. (2004). "On-the-fly programming: Using code as an expressive musical instrument". Proceedings of the International Conference on New Interfaces for Musical Expression. http://soundlab.cs.princeton.edu/publications/on-the-fly_nime2004.pdf. 
• Wang, G.; Cook, P. (2003). "ChucK: A concurrent, on-the-fly audio programming language". Proceedings of the International Computer Music Conference. http://soundlab.cs.princeton.edu/publications/chuck_icmc2003.pdf. 

Seemingly independent coverage

• Graham Morrison, (2009) Generate choons with Chuck. Tired of the same old music in the charts, we create our own music from a series of pseudo random numbers. Linux Format issue 125
• Alan Blackwell and Nick Collins, The Programming Language as a Musical Instrument in P. Romero, J. Good, E. Acosta Chaparro & S. Bryant (Eds). Proc. PPIG 17, pp. 120–130
• R. T. Dean, ed (2009). The Oxford Handbook of Computer Music. Oxford University Press. pp. 27 and 580. ISBN 978-0-19-533161-5. 

External links

• ChucK homepage at Princeton University
• ChucK mirror at Stanford University
• ChucK FLOSS manual