This is a collection of web-based algorithmic composition toys, written by Tim Thompson. All of them make use of the KeyKit programming language for processing and producing MIDI music. The source code for most of the tools is viewable from each tool's page. The most interesting toys are noted with .


In this toy, you enter a word in a form, and get back algorithmic music based on that word. The algorithm is deterministic, so entering the same word will produce the same result. There are two algorithms to choose from - algorithm A produces melodics results, algorithm B produces more atonal results. Muse-O-Matic was the very first tune toy.

Key Chain

This toy is very open-ended and much less "canned" than the other toys. You specify a series of transformations on a musical phrase. Initially there are no transformations, and you add them one at a time - they are applied in series. This toy gives you a flavor of the things you can do, algorithmically and interactively, with the KeyKit software.


This toy takes an existing MIDI file, splits it into pieces, and puts it back together to produce a new MIDI file. To use it, you enter a URL for a MIDI file (anywhere on the web), and it gets processed to produce another MIDI file. You can control the number of pieces that the MIDI file is split into.

MIDI Mixup

This toy, like Pieces-O-MIDI, takes existing MIDI files and processes them. In this case, three MIDI files get combined - one is used for pitches, one is used for timing, and one is used for durations. The files are combined to produce another MIDI file.


This toy produces wildly varying music. By using an L-systems (fractal) algorithm, simple expressions (literally just the variable X) are mutated to produce extremely long and complicated expressions - still in terms of a variable X. A note, small phrase, or chord is substituted for the variable X, and the expression is evaluated. The result varies wildly. This is one of the best Tune Toys, in terms of producing suprising and unusual output.

Fresh Roast  

This toy extends and refines the algorithm used in the Expresso toy. Algorithmic drum patterns have been added, and up to 8 tracks (each track using a different random sound) are generated and combined. Every measure is generated independently, including patch changes, so that the results change continuously.

Life Forms

This toy uses John Conway's "Game of Life" to generate music. The game involves a matrix of cells that evolve one "generation" at time. There are rules that govern whether a given cell will live, die (from over-crowding), or be born. This toy takes each generation and converts the cells into notes. The result is a melody that evolves.

The following aren't really "toys". One is a repository for the results of other Tune Toys, and one is a general collaborative area for uploading and sharing bits of music.

Tune Trove

A repository for good tune toy output.

Composer's Quarry  

This was a web-based collaborative interface - upload MIDI and MP3 files to various areas, and interact with other composers. It no longer works.