Mentioned this briefly on Twitter, and it’s by no means recent, but I thought it was worth a repost here as I found it immediately motivated me to get deeper into Quartz Composer. In short, it epitomises what a tutorial should be—it quickly allows you to do something cool that both gives a hint of what further possibilities lie ahead, and is worth showing off to people. In this case, creating a rotating, lighted cube that changes height in response to audio input.