Yes and no. Classical music doesn't have a monopoly on music but I wouldn't call "Let's Get Retarded" deeper. A message does not have to expressed in lyrics, or even be a concrete thing. Saying that one piece of music is better because it has lyrics, going back to your soda metaphor, is like saying coke is better then pepsi just because coke has better content on it's label. People who say that the 5th symphony is deeper point to the greater depth of composition, direction of the music and emotion built in it. It is not any less deep because it doesn't hit the listener over the head with its message.
Bookmarks