Why you can’t play 2x bass pedal songs online with friends in Rock Band?

If you cannot play a 2x Bass Pedal version of a song with a friend online, it is likely because they do not own the same version.

The 2x Bass Pedal version and the standard version of a song are treated as separate tracks. Both players must own the same version to play together online.

Note: This applies only to legacy Rock Band titles. 2x Bass Pedal versions are not available in Rock Band 4.