I watched this twice I’m still not entirely sure I understand what’s going here. Still, it’s an impressively unique idea. Here’s the explanation from Makezine.com:

What would the trunk of a tree sound like if a cross section of it were played like an LP? With his creation Years, Bartholomäus Traubeck attempts to answer that question by using a turntable, PlayStation Eye Camera, a stepper motor to control the arm, and computer running Ableton Live. As you’ll hear in the video above, the rings of the tree trunk, as interpreted by this piece, create an eerie and ominous piano track that sounds like it was taken from psychological horror film. Who knew trees were so emo? [via Creative Applications]