Rock Band made a staggering 6 million downloads in just four month since its official launch, and continues to conquer the hearts of music and game fans by offering them an impressive selection of ‘best of the best’ songs to date. So far, the videogame went six times platinum and is not planning to stop just now!

Since November 20, 2007, Rock Band, which was released by MTV Games and Harmonix and distributed and marketed by EA, continued to offer for $170 (full package) a music experience that kept videogame fans on a shopping spree. MTV and Harmonix also announced a new software patch this week, which will feature an in-game Rock Band Music Store and will allow users to build their own custom Rock Band library.

“The success of Rock Band downloadable content to date firmly reinforces our vision and its potential as a platform for music discovery. 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,’ said Paul Degooyer, SVP DVD, Gaming and Audio, MTV in a statement.

The new Rock Band Music Store will offer a user-friendly interface to offer a whole new experience to music shoppers, and at the same time, will become available through free downloads via Xbox LIVE and PlayStation starting this week. The Music Store will have its library sorted by Artist, Song, Title, Genre, Albums, Pack, together with detailed information on the song and the difficulties for each instrument, the company unveiled.

Starting this week, fans will get a fresh new load of songs every week, available through download purchase, with a retail price that will vary between $.99 and $2.99 per track (or 80 to 240 Microsoft Points for the Xbox 360).