> I can play anything by ear, I wonder if that's usual for hacker types.

I think it has more to do with how you learned the instrument. Most classically trained pianists I know couldn't sound out a Doors tune to save their life. On the other hand, once I started playing in bands, just about everybody I met could listen to a song and have it figured out within an hour.

I (a hacker type) was better than most classically trained types at sounding out music, but still had difficulties compared to most people in the band circuit. I usually couldn't really nail a part unless I found the music in a magazine somewhere. (this was pre-Internet, today this wouldn't be an issue)

I have very little training myself, but my grandmother is a "classically trained type". She was a cellist at Oberlin Conservatory and has perfect pitch. I can send her into another room while I hit six keys on a piano and she can name all the notes. I can kick a metal garbage can and she can say what notes the resulting sound are closest to. While I was studying piano for a short time myself, I tested her abilities pretty thoroughly. Writing out (or just playing) a pop song is trivial for someone like that.

From what she's said to me, those skills weren't that exceptional. Many good strings players have perfect pitch, and even those who don't or those who play other instruments have excellent relative pitch. I don't see how a classically trained pianist would have problems with a Doors tune, especially considering how few chord progressions pop songs use.