Dutch coder and digital detecive Yvo Schaap did some digging in the code underneath Facebook over the weekend and came up with a list of services particpating in Facebook Music which sources say will be announced Thursday. "I looked at the major music streaming services, and found an interesting reference in their HTML code." said Schapp. "All track, album and artist pages got meta data in a yet undocumented format." The Facebook Music services include:

• Spotify
• MOG
• Rhapsody
• Soundcloud
• Rdio
• Deezer (France)
• VEVO

Other sources have confirmed most of what Schaap found. "These services providing detailed meta data regarding music, which users could like, share and comment would be a big win for Facebook and other developers to build from," according to Schaap. "The social graph would be expanded by a detailed music profile of users, and their friends."