Tom Shales

Making music on TV used to be as common as commercials. In the '60s and '70s, prime time was stuffed with variety shows headlined by such major and treasured talents as Carol Burnett, Red Skelton, the Smothers Brothers and Richard Pryor, who had a very brief comedy-variety hour on NBC that was censored literally to death.

Tom Snyder was born to broadcast. He loved television and it loved him back. In that, he was a member of a vanishing breed, especially as narrowcasting displaces broadcasting, 'online' replaces 'on the air,' and any Tom, Dick or Mary can be monarch of a desktop domain, uplinking themselves to satellites in space.

Jerry Seinfeld is amazing in many ways, not the least of them his ability to find humor, and convincing us to find it, too, in the million-and-two details about modern life that under different circumstances might send us into paroxysms of rage.

What do cells do when they see a broken piece of DNA? Cells don't like such breaks. They'll do pretty much anything they can to fix things up. If a chromosome is broken, the cells will repair the break using an intact chromosome.