it's obvious that some songs don't need a focus on intellectual appeal or even harmony to be good -- but it's just that a song that can do all of it brilliantly would be just that -- deserving of a near 100. Has any been created yet? Hmm...
30% (any category or overall) = tolerable
50% good enough to go on a playlist
70% great playlist item
90%+ did I say masterpiece?
intellectual appeal 15%
harmony and aesthetics 22%