This is great! So many musicians I know scoff at pop music, but it wouldn't be popular if there wasn't something to it. I don't know why people are so quick to dismiss the amount of work that goes into a musician's career, no matter what the genre... Anyways, I've read a lot of songwriting books referencing pop music for lyrical content and structure, but this is the most in-depth I've seen for the actual music theory behind it. Great article!