Any why? There's certainly aspects of both that are harder/easier than the other * Guitarists can use a single 'scale' and change keys by just sliding up/down the fretboard. Pianists need to memorize 12 distinct scales to do the same (electronic boards with pitch-control knobs not withstanding...). So +1 on 'piano is harder'. * A single note can be played in one & only one location on a piano. If ya want a "C4", there's only one way to do it. On guitar, we have to memorize at least 3-4 different places to play any given note. +1 for guitar. * On a piano, you can hit the key harder or softer, but you can't do things like vibrato, bends or slides. If you hit a note, it's "on pitch" automatically. Bend a note on guitar, and you have to have a good enough ear to tell if you're bending it to the proper pitch. +1 for guitar * Pianists often play two distinct parts at the same time. Running a bass-line with the left hand, melody with the right. I honestly don't know how the hell they do that. +1 for piano (maybe +3....) * For a piano to 'sound good', it just has to be in-tune and be an instrument of reasonable quality. I never hear of piano players chasing "tone" like guitarists. For an electric guitar to 'sound good', you gotta be able to dial-in all those knobs and such ... It's easy to make a great rig sound like an elephant farting, but you really can't screw up a piano's tone. +1 for guitar What else ya got????