I’m running “Phasers on Satie (Long Phase)” on STAPLR for a while. It uses the left-hand riff from Vexations by Erik Satie, normalized so all the notes are the same length. There are eighteen notes, and it’s running at 54 beats per minute, so it plays three times a minute.
Every time there’s an interaction at one of the York University Libraries desks, the piece begins to play for as many minutes as the interaction was long, but after the first time the riff is played it starts to go out of phase, and gets a little more behind every repetition. The phase length is such that the first note is just about to run into the second note by the time the repetitions are done, but it stops one repetition before that happens. Because the interactions at the desks start at different times and last for different durations, many different types of patterns can crop up.