During the original Destiny's early years, then-composer Marty O'Donnell, composer Mike Salvatori, and Sir Paul McCartney (who is likely a canonical part of the Destiny universe) came together to create Music of the Spheres, a sort of musical accompaniment to the game (not to be confused to the game's actual soundtrack). The project was never fully released due in part to a rift between O'Donnell and Destiny developer Bungie that eventually spawned a legal case. Now, however, it's been leaked online.
The project is available on music website Soundcloud. Last month, O'Donnell tweeted that before the project was shelved, he gave away "nearly 100 copies" of Music Of Spheres. According to Kotaku, two fans who had attempting to the project from publicly available bits of the music were contacted by an anonymous owner of one of those copies, and have released the soundtrack online.
It's likely Activision or Bungie will issue a takedown notice soon. For his part, however, O'Donnell seems supportive of the leak, tweeting both a photo of someone playing the songs on their computer and gratitude about Music of the Spheres being available.
To learn more about Music of the Spheres, you can check out our cover story feature delving into the project.