Shit is subjective. Prince had a unique voice and it blended exceptionally well with his musical style. He could definitely sing, just didn't have a traditional voice. Keith Sweat couldn't sing. Al B Sure debunked the falsetto debate, that Dude definitely couldn't sing. Prince displayed a technique and a range that showed that he intentionally modded his voice to support his music. Luther could sing, but can you imagine him covering Prince songs? Shit would be awkward sounding as hell... Prince could sing, just not in the 'classic' sense, which is what made him vocally special...