You've got to check this out. It's called "In Bb 2.0". It's a sort of internet/youtube take on Terry Rily's "In C", but with you control the pace with a whole number of musical parts. None of this is mine. It's all the brainchild of Darren Solomon (website / twitter) who used youtube and collaborators who post music in Bb. It's gorgeous and you can spend most of your life just recombining the musical lines (there's 1.55 * 10^25 permutations). Below is just a four piece taster that you can arrange in 24 different combinations.