Note blocks, which play a tone in one of two octaves, were added to Minecraft with the PC hit's update yesterday. Already someone's figured out how to make them play the introduction to the Portal theme "Still Alive."
YouTube poster Tritex989 made the music machine, which plays automatically thanks to redstone powering each note block. "I didn't continue it, 'cause i would be forced to only play the melody and that would sound too simple in my opinion." he wrote.
Other experiments have popped up on YouTube as well. Here's the Harry Potter Theme, though it's not redstone-powered, so the user has to activate each block.
How long until the inevitable Super Mario Bros. theme? If you've got the time on your hands, the Minecraft Wiki breaks down how to set the notes for each block and which block provides which of four percussion equivalents. The harp sound is the only musical instrument.
Thanks to Ryan H. for the tip!