As demonstrated in the comic strip “Pearls Before Swine”:
remember “Sing Along With Mitch”?
Mitch was a few years before my time. 
As I remember it they sang that song at the end of every episode, with their own abrupt ending:
“,Now you may think that this is the end, Well it IS!”
Sing Along With Mitch was brilliantly parodied by the incomparable Jonathan and Darlene Edwards (actually the incredibly talented Paul Weston and Jo Stafford, playing incredibly untalented characters). Consider this:
Tiptoe Through the Tulips
Carioca
They won a Grammy in 1960 for comedy. Mitch Miller blamed the couple’s 1962 album Sing Along With Jonathan and Darlene Edwards for ending his sing-along albums and television show. Them’s the breaks, Mitch.
To be fair to her memory, here’s Jo in her real voice:
I’d like to mention WKRP End Credits too. A search gave multiple versions of the actual words, but this one seems closest. The musician had the rock theme written but no words, so he put in nonsense words, at first figuring he’d write better lyrics later, but thought it funny as is, knowing the broadcasting station announcer would be talking over the closing credits anyway.