Bungie has released one of the music tracks from Destiny that was featured at E3. It's not the track that played during the game's demo (which you can see here), but rather the music that played in the Rotund. The Rotund was an Activision instillation at E3 that featured a sort of rounded theater where footage from Destiny was shown. The track that played in the theater is now available to listen to, or download.
As you might expect, considering Bungie's musical track record, it's pretty great. Head here to listen to it.