I made Confetti in celebration of my birthday. It's playful and free. The lack of correlation between pitches and colours is a liberating step for me, I would have previously been inclined to match them according to my synethsesic preferences. Not doing so makes me hear the sounds in a whole new way. "Who would I be if this note really did feel red?"
Press play on the air track. Then, press play on any of the confetti videos whenever you like.
In a group
One person loads and plays the air track. Each of the other people load one of the confetti videos on their phones and play it full screen whenever they like. Gather the phones in a bunch.