I don't deal with sheet music especially well. I can read it, but excruciatingly slowly. Put me at a piano, and I can pick out -- with one finger, at great and usually boring length -- the notes, although I will have absolutely no idea of the timing, and it won't sound like music unless I've heard the song before.

I can recognize some of it from half a mile away. This is Chopin. I have no idea what it is or what it sounds like; I'm not the guy who could 'read' records by looking at the grooves. Pretty much everything by Chopin looks like that to me, with a strong running pattern throughout the page. The repeats are long, but not too long, and the motifs are prominent. Some of it is messier than others, with spotty patches of other patterns breaking through around the main one, but pretty much all of it, if I step back and see the page as a series of intertwining functions instead of a spatter of individual notes, looks like it has a path.

Compare Beethoven. There are some patches of pattern there, in what the title informs me is Für Elise as if I am going to know, but it changes too rapidly to be visible from squinting-at-a-thumbnail distance. The repeats are either very short and never cycle more than a couple of times, or they're so long they don't fit on one page and can't be visually compared.

I don't mind Beethoven. I mostly don't mind the Classical and Romantic composers, although I couldn't pick them out of a lineup, aurally. Unless it's a super-famous piece, like Beethoven's Fifth Symphony, I will have no idea what the hell I'm listening to, other than it's kind of pretty and interesting.
It works with pop composers too, if the composer is distinctive enough. Once upon a time, I was a miserable failure at teaching myself to play the guitar. I have a variety of brain-quirks around music that, while interesting, were not conducive to figuring things out without help; one of them is that, as mentioned above, I can't reproduce anything I haven't heard before, because sheet music means nearly nothing to me and even counting doesn't help me figure out how the lengths of the notes fit together. Most lesson books have folk music in them, and after establishing that no, I don't fucking know how "Sweet Aura Lee" is supposed to sound, I broke down and bought one that was nothing but the Beatles, whom I've been hearing since shortly before my conception.

Just flipping through the book, I can tell which songs are by John Lennon, and which ones are by Paul McCartney. Everything either one did for the Beatles is officially credited to both, a handshake deal from the very beginning that both of them actually honored even when they hated each other for a while there, but they look very different when written down. (Complicated somewhat by the fact that neither of them were doing the writing -- they were all more or less self-taught and didn't read sheet music. So far as I know, Macca still really doesn't. Their producer, a classically-trained musician, did the writing if they needed to give anything to session musicians.) The things McCartney writes all either sit on a rolling sequence or hang from one; Lennon is not as predictable.

It carries over to purely-aural identification at times. Shiina Ringo is a big fan of Lennon, as is Ozzy Osbourne. Paul Doucette sounds like a much pointier Paul McCartney. And Rob Thomas has developed a tendency to channel Michael Hutchence.

I'm not really surprised at all this, being as I do most of my deductions and people-reading through what is essentially a lot of very complicated analogies, but it apparently weirds other people out when I take a blind stab at guessing something and turn out to be right. I do it a lot with languages, but occasionally I get some really impressive hits on other things.