TidalCycles (also known as Tidal) is a live coding environment which is designed for improvising and composing music. Technically, it is a domain-specific language embedded in the functional programming language Haskell, and is focused on the generating and manipulating audiovisual patterns. It was originally designed for heavily percussive and polyrhythmic grid-based music, but it now uses a flexible and functional reactive representation for patterns, by using rational time. Therefore, Tidal may 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.