Send us Fan Mail After considering why companies run out of ideas in our last episode, Joe put the same question to Mark about why so many of our favorite pop and rock music artists seem to run out of ideas. Mark and Joe ponder whether this is a real phenomenon, and if so, what might cause it. Turns out that early-career creativity is a complicated amalgam of neural plasticity, free time, and the commercial imperatives of a pop music industry that skews young. And yes, Clayt...