Hey @gamingonlinux have you covered Clone Hero before? It's a great Guitar Hero clone that works with USB guitar controllers and can use songs from Frets On Fire among other formats. Supports Linux/Mac/Windows: https://clonehero.net/
I just discovered it this morning, and as a Guitar Hero/Rockband addict... um... productivity is in danger...
@gudenau @gamingonlinux maybe if we bribed them? Do they have a ko-fi on or something?
@Taffer @gamingonlinux It's also got some glaring issues that the developers don't care about fixing and tell you off for wanting them to fix it. :-)