It's easy to say that reducing a song to 90 seconds on "American Idol" strips off so many things, and how it's the 21st century and music doesn't mean the same things to people and that it's so disposable.
A rock band is a mysterious thing. Somehow, every once in a while, a few individuals bump into one another, and they look exactly right together and share a focus and an aspiration and the right balance of musical similarities and differences.
In country and R&B, there's much more of that division between writers and performers, and that's where you see more of those [crossover] songs, but you don't get a lot of that coming out of the more pop and rock side of things.
After the Beatles and Dylan, there's this assumption that you are a singer-songwriter, or that if someone else is writing your rhymes, you're a fake rapper.