prince was the most talented musician to walk the earth, he could play every instrument fluently, and wrote all his songs.
One of the things that made Prince great was his creativity. No one cares about how many instruments an artist can play if the songs suck.
I've heard musicians say most of Prince's guitar parts are fairly easy to play, but when they do they doesn't sound half as good as the original. It's not just about what you play, how it's played makes a huge difference.
As for his skills as a drummer, he was an okay drummer. Good enough for getting the job done on most pop songs, but he was far better on (bass) guitar and keyboards. Candy Dulfer mentioned he played sax rather poorly, which was surprising since no one even knew he played horns at all. AFAIK he never played sax on official records, only demo's.
Anyway it's all relative. Quincy said it best:
A lot of Prince fans were pissed when they saw that clip, but when someone like Quincy who has worked with the best musicians thinks you're an okay piano player, well IMO that's a compliment. He's comparing Prince to people who played piano all day, every day.
