Official Xbox Magazine will have three "completely exclusive," albeit obscure songs for Rock Band. The disc contains Freezepop's Sprøde, Bang Camaro's Rock Rebellion and Count Zero's Shake (like our Rock Band weekly feature, we've placed videos of the songs after the break; though we're currently missing Shake).
OXM Editor-in-Chief Francesca Reyes tells Joystiq, "You'll be able to download the songs from the disc onto your [hard drive] and they will remain there with or without the disc in the drive." Does this mean Harmonix could eventually offer retail expansion discs stuffed with songs? That idea is pure speculation, but we'd welcome it in lieu of a full-priced 'Rock Band 2.'