'The Sopranos,' for instance, is arguably the best cable show of all time. They could have made a movie, but that show ended so perfectly, it would almost be a disadvantage to make a movie like that. Then again, if you made a 'Sopranos' movie, people would be lined around the block to go see it.
So writing a song is much harder than doing a classical piece for me, because in a classical piece, I can just let the mood dictate what's going to happen.

