The final portion of Portal 2's Songs to Test By album is ready for download, covering the last act of the single player campaign and multiplayer mode. In case you were wondering, this part of the album does feature the two catchy ending tunes. Feel free to pull up any of these songs while playing the "Peer Review" DLC that's coming soon.
You can find a download link in the source below. Also available is a single, complete album download in case you missed out on getting the previous two volumes.