This always cheers me up at least a little.
Pete Seeger, Pat Sky, and the Pennywhistlers performing "No Sir, No" on "Rainbow Quest".
The best part is that they rapidly run out of verses they know, so Sky substitutes some from another song, and then they still have more time on the clock, so Seeger starts to make stuff up. I've been there!
The best part is that they rapidly run out of verses they know, so Sky substitutes some from another song, and then they still have more time on the clock, so Seeger starts to make stuff up. I've been there!