The most recent Minecraft update added a number of things, from the useful (tool durability increase), to the pointless but pretty (dyes for wool). One item was the curious Note Blocks, which play a note when activated and can have their pitch changed. Depending on what block they're placed on top of, they'll play a different instrument which gives quite a variety of results. I've already seen "Still Alive" from Portal, and Michael Jackson's "Billie Jean", but by far the most impressive has to be a video simply titled "Minecraft Rave" which I've embedded after the break.

Minecraft has evolved from "Survival-Horror LEGO Harvest Moon", to something even more ridiculous that I don't even want to think about a name for; and I love it.

http://www.youtube.com/v/RuWW9bEfzvs?fs=1&hl=en_US