For me, the most difficult thing is that I am learning melodies on guitar from some songs whose melodies were not meant to be played on guitar. Ever. They were intended mostly for keyboards or melodic percussion.
Dweezil ZappaWhile it is true that Frank had a great sense of humor, he was also very serious about composing music. In reality there are only a handful of skilled players who can play his most complex pieces. It takes a lot of patience to learn and requires a fantastic memory.
Dweezil ZappaIf you only ever heard "Valley Girl," or "Don't Eat The Yellow Snow," or a song that has a comedic narrative, you would get some impression that that was novelty music, but that's the only stuff that ever got on the radio. You can make the argument that that's what has confused generations as to what his music's about.
Dweezil Zappa