Tom Waits singing Young at Heart is not an anomaly. The songs he writes are often in that mold, a fact that most people have missed because he doesn't have the kind of voice that singers of that music usually had. If he did have that kind of voice, the idiots who buy rock music wouldn't listen to him.

Sun Ra pulled a similar stunt. He played straight-up swing jazz most of the time, and played it very well. But the musicians wore colorful costumes that suggested a cross between extra-terrestrial and primitive villager, instead of the suits that swing jazz bands always wore. Sun Ra's fans would have taken the suits as a signal that they shouldn't like his music, and if anyone had told them they were grooving to the kind of band that Bing Crosby sang with they'd have been horrified. To ensure that wouldn't happen, the Arkestra periodically diverged for a short time into random sounds that fit in with their costumes. So young people were able to enjoy the music their parents or grandparents thrived on, but without feeling square.

Dylan doing crooner songs is something else entirely. Not only does his voice lack the finesse, but the songs he wrote are crude in comparison, as are folk songs. But since he's so popular, there's some benefit in his release of an album of Tin Pan Alley songs, just as there would be if Paris Hilton performed Moliere. It would expose contemporary masses to something from the past that they'd otherwise never know about. Of course it won't sound good. The only time Dylan ever sounded good was when he sang Froggie Went a-Courtin'.