The install size for Rock Band 4 has been revealed coming in at 10.23 GB on the Xbox Marketplace and will include some backward compatible instruments along with 1500 past songs. The game will released on October 6th featuring 1-4 player multiplayer offline and online as you rock the virtual world together. The library continues to expand monthly with new songs and changes to rocking experience. It also has an expansion of Rock Band Rivals that adds a new mini campaign.
Xbox.com Marketplace Storepage (Showing on Site)