Cambridge (MA) - MTV and Harmonix have announced that their addictive multi-controller music game has seen success with additional downloadable content, with over six million tracks purchased in just four months.

"The success of Rock Band downloadable content to date firmly reinforces our vision and its potential as a platform for music discovery," said senior VP of MTV's home media unit Paul DeGooyer.

Because of the success of downloadable content, Harmonix will introduce a new update for Rock Band that will allow users to browse and purchase new songs directly from the game menu.

Additionally, the update will let users listen to free previews of all available songs.

"By empowering players with the ability to customize their Rock Band library with a rapidly growing selection of rock artists and songs on a weekly basis and adding great new features such as the in-game music store, we are thrilled to give fans more ways to enhance and enjoy their Rock Band experience," sai DeGooyer.