If you don't have anything to say, don't say anything

I spent a few years as a radio disc jockey, and when I first started I was told that this was the first rule of radio, although it was phrased a little differently:

"If you don't have anything to say, don't say it."

In other words, listeners don't want to hear you try to be funny, or stumble around spewing music trivia. They just want to hear their music, so get on with it.