"It is not unusual that musical guests do not speak with Letterman."

That's very true, but there have been exceptions over the years ~ not many, and not very often, but for truly "exceptional" musical personalities.

When a relatively unknown rock band is the "musical guest," as is most often the case, they certainly do not get a sit-down.

But there have been instances where important, iconic artists have appeared in both "roles," as regular interviewed guest and also performing in the final-five-minutes musical-guest time-slot. One example, off the top of my head: Tony Bennett. There have been others I can't think of right now.

Pete Seeger certainly could have been scheduled for that kind of treatment, but if that were the case, he would be one of two guests, not one of three. So as soon as I saw that two other show-biz personalities were on the program, I was pretty sure that Pete would not be seen/heard until the end.