Congratulations! You, an aspiring musician, have been visited by Truck-kun, god of interdimensional travel. You find yourself in a world that is not your own, and all of your modern conveniences have been replaced with powerful magics and hard steel. While this certainly changes some of your future plans, you take it in stride. Instead of being consumed by the many things you can no longer do, you see great opportunity in a world that has never before heard the heart wrenching ballads of Freddie Mercury, the frantic fingers of Eddie Van Halen, or the brutal percussion of Mario Duplantier. You decide to do what you've always done - you start a band, and you're going to be a hit.
Design the tools you'll use to make your dream a reality. Fantasy instruments (whether versions of modern instruments, or something entirely different), accessories like magical amps, microphones, music halls with all the right acoustics, or the stage dressings and costumes to give your audience the greatest show they've ever seen.