Rock Band Companion is a free, fan-made companion app for the game Rock Band 4™*. Check out the latest Rivals challenges, keep track of your music library, and find optimized overdrive paths to maximize your scores.This app was made possible due to the existing work of other Rock Band community members. Song data is compiled from rb4.app*, and path data is fetched from Rock Band Path Vault (rbpv.online).*Rock Band 4™ is a trademark of Harmonix Music Systems, Inc. Rock Band Companion is not affiliated with Harmonix Music Systems, Inc., rb4.app, or Rock Band Path Vault.