"canon ad libitum" by Joâo SCHNIER is shared under Creative Commons Attribution-NonCommercial-ShareAlike 4.0. canon ad libitum is a simple and repetitive piece. The same melody ( two broken arpeggios) is played by four voices with a semiquaver of phase between each voice. The music repeat ad libitum for a long time. Various instruments can begin to play any voice at any moment, for any amount of time. At the end, instruments currently playing go on the last bars and finish.

Score freely and legally available here : http://imslp.org/wiki/Canon_ad_libitu...

Sorry for the bad quality, the hardware simply doesn't want to get it correctly.