According to a NASA report issued last Friday:
... Endeavour crew members, Commander Chris Ferguson, Pilot Eric Boe and mission specialists Don Pettit, Steve Bowen, Heidemarie Stefanyshyn-Piper, Shane Kimbrough and Greg Chamitoff, and the station crew, Commander Mike Fincke and flight engineers Yury Lonchakov and Sandra Magnus, were awakened at 8:05 a.m. CST.
The music was for Piper. The song was in the Ukrainian language, which she learned as a child. It was "Unharness Your Horses, Boys," ... performed by The Ukrainians.
The full NASA STS-126 Report #14 report can be read here.