Velato (2009)

Velato is a programming language which uses MIDI files as source code: the pattern of notes determines commands. Velato offers an unusual challenge to programmer-musicians: to compose a musical piece that, in addition to expressing their aims musically, fills the constraints necessary to compile to a working Velato program. Each song has a secret message: the program it determines when compiled as Velato.

Velato on

A three-part introduction to the language on my blog:

Download the compiler

Create Digital Music's coverage of Velato

Velato is currently Windows-only, and requires the .NET Framework 3.5 to run.

This is freeware, do whatever you want with it; just don't sell it.

This download includes the compiler itself, and Stephen Toub's MIDI library, used to read the .mid files.