Bono has a nice piece in this morning's New York Times about the legacy of Frank Sinatra:
Like Bob Dylan's, Nina Simone's, Pavarotti's, Sinatra's voice is improved by age, by years spent fermenting in cracked and whiskeyed oak barrels. As a communicator, hitting the notes is only part of the story, of course.Singers, more than other musicians, depend on what they know -- as opposed to what they don't want to know about the world. While there is a danger in this -- the loss of naïveté, for instance, which holds its own certain power -- interpretive skills generally gain in the course of a life well abused.
You can read the whole thing (or even better, listen to Bono deliver it) here.