Wikipedia
TidalCycles (also known as "Tidal") is a live coding environment designed for musical improvisation. In particular, it is a domain-specific language embedded in Haskell, focused on the generation and manipulation of audible or visual patterns. It was originally designed for heavily percussive, polyrhythmic grid-based music, but now uses a flexible, functional reactive representation for patterns, using rational time. Tidal may therefore be applied to a wide range of musical styles, although its cyclic approach to time means that it affords use in repetitive styles such as Algorave.
In its native configuration, Tidal triggers samples on disk via a C-language sampler called Dirt . However there also exist integrations for MIDI, and for the SuperCollider sound environment.