Interesting comment from this article on why humans are so good at recognizing music:
The subtlest reason that pop music is so flavorful to our brains is that it relies so strongly on timbre. Timbre is a peculiar blend of tones in any sound; it is why a tuba sounds so different from a flute even when they are playing the same melody in the same key. Popular performers or groups, Levitin argued, are pleasing not because of any particular virtuosity, but because they create an overall timbre that remains consistent from song to song. That quality explains why, for example, I could identify even a single note of Elton John’s “Benny and the Jets.”
“Nobody else’s piano sounds quite like that,” he said, referring to John. “Pop musicians compose with timbre. Pitch and harmony are becoming less important.”
(Thanks to Janie for the link!)