[nileshtrivedi]

Very interesting! Although, for most common chords chart, I think that instead of simply counting the number of times a chord appears, you should have also considered the duration of that chord in the song.

Didn't Pandora radio did the same analysis for its recommendation engine?

[freehunter]

Yeah, I play guitar as just a personal hobby, and there are a lot of times when I'll play an "in between" chord on my way to the next chord I would consider to be in the progression. Many times it's not a traditional "chord" you would find in this list, but just something to bridge a key change or just create a feeling of movement.

I would say that this is most often limited to music that falls outside of pop culture, though. Katy Perry doesn't need to create movement or flow because emotional expression on the backing track is not what her music is about. The Raconteurs might, though. But once you get to that point you have to make the distinction between notes and chords.