Mixed Signals got several comments from listeners about All Things Considered director Bob Boilen's work picking music interludes — "buttons" — to run between stories. The posting wasn't meant to be an exhaustive explanation and thus, may have left the impression that it's just "something we do." In fact, all our programs — All Things Considered, Morning Edition and Talk of the Nation, to name a few — have to be perfectly timed. They are sent to member stations and those stations have to fit us in along with their own news, music, traffic alerts and so on.
Now, I can tell you from experience, you can't write a five-minute story with taped interviews, then read and record it, and be sure it's exactly 300 seconds. It's quite impossible with live interviews. There's a little "drift" timewise in each story. Add four or five stories together in a segment, and you may have quite a bit of drift. And if it's a last-minute crash on a late-breaking news story, reporters are hard-pressed just to get it right and clear, let alone down to the second.
So when a piece or segment comes in a few seconds short, you can either listen to dead air... or a little music. So music keeps gaping black holes out of our shows.
That said, Bob points out that the music has a lot of fans. We like to think that it gives listeners time to absorb what they've just heard before galloping on to the next story. We sometimes hear from our colleagues in commercial radio that NPR is somewhat "calmer" and slower-paced than their medium. We like it that way — and the music helps make it that way.