If you're a rock star whose defining work came out somewhere between the years of 1969 and 1994, chances are your body and soul have atrophied into tiny prunes thanks to a decades-long carousel of hedonism.
We all kind of expect nowadays that the person singing a tune we're into likely didn't write it. What's shocking, though, is that sometimes the song was written by someone who likely could've performed it better as well.
What sucks about the entertainment industry is that usually a very small group of very pretty people get all of the credit for work done by an army of talented folks behind the scenes.