No, actual music. Stone would sound stupid. Even if you drop a few of them on the floor at the same time they still just kind of go 'DUNK'.
According to another site these songs have been identified:
Creedence Clearwater Revival Fortunate Son
Wagner Ride of the Valkyries
Wolf People Village Strollin'
Jack Arel Picture of Summer
Jack Arel Strange Galaxy
Jack Arel L'Amour Et L'Enfer
John O'Brien-Docker Freak Out
John O'Brien-Docker Sock it to Me Baby
Pierre Dutour & Jack Arel Bewilderment
Anders Lewen Muscle Soul
Anders Lewen Memphis Guitar Soul