Artist: Two Hours Traffic
Track: Jezebel
Scene: Opening
iTunes US:

Artist: Bach
Track: Toccata and Fugue in D Minor
Scene: Castle's ringtone when Beckett calls
iTunes US:

Artist: Brighton, MA
Track: Graceland '02
Scene: Castle watches Alexis sleep / asks if she's doing drugs
iTunes US:

Artist: Alex & Sam
Track: Buy Your Side
Scene: Alxis wakes Castle with a confession
iTunes US:

Artist: Eric Hutchison
Track: Food Chain
Scene: Ending/Martha's party
iTunes US: