Harmonix and MTV Games have announced that an eight pack of songs from R.E.M. and a three pack of songs from T. Rex will be added next week to the Rock Band Music Store of downloadable content for Xbox 360, PlayStation 3 and Wii. Rock Band provides the best selection of artists, songs and albums through the Rock Band music platform, which features more than 800 artists and almost 2,000 tracks via disc and download purchase.