Rock Band Network for Xbox 360 has now entered open beta.
The service invites musicians to upload and sell video game versions of their tunes. Songs are priced between 99 cents and $2.99, with the artist set to receive a 30 per cent cut.
Harmonix hopes the service will attract unsigned artists, although it is also being used by established bands such as Creed and Evanescence.
"We expected this to be an initiative that would appeal to unsigned artists," MTV's senior vice president for electronic games and music Paul DeGooyer told then Wall Street Journal.
"What was surprising to us was how many artists with hit records have offered themselves up."
However, the Wall Street Journal speculates that the service might be too costly for new artists, with many having to use costly contractors to format their songs for Rock Band.