Orca[1] is like a moving 2D functional programming crossword puzzle for generating sequences, be sure to watch some tutorial videos to get started.
TidalCycles[3] is a lovely way to very concisely and quickly generate looping patterns of samples and tones, still getting my head around it.
[0] https://twitter.com/neauoire
[1] https://hundredrabbits.itch.io/orca examples on twitter: https://twitter.com/hashtag/ORC%CE%9B
[2] https://twitter.com/yaxu
[3] https://tidalcycles.org/ examples on twitter: https://twitter.com/hashtag/TidalCycles