"any way we could upload a sound (with max size wav or mp3) at the same time we upload the painting. then it play the 8 tracks synchronised. with a button to turn off sound yes."

curiously, we had almost this *exact* thing set up with hygrid! you could upload a sound file and then "mix" several tracks (turn on/off) while viewing pieces of hygrid. it kinda became both confusing and unused, so we dropped it.