Harmonix has announced Rock Band Network, which launches in August, a new network that allows anyone who pays the fee for a Microsoft XNA Creators Club account to upload their music to Rock Band and create their own playable game track for download in the music store. This is obviously a big deal, since it opens up Rock Band to a multitude of bands, and will allow undiscovered bands to have more publicity via a videogame. There's a preview video above in case you're interested. [Hypebot]