You know the 4-note lead-in that's played at the start of the first (but not the second) time the musical phrase is played by the "one-man band"? It goes "da-da da DA".
Those same notes were later reused in one of those short "commercial" letter animations. Typically these went:
<letter>.
<word starting with letter>.
(funny animation involving said word).
<letter>.
The musical notes -- probably the original ones -- were played after the final recitation of the letter. I think it was the letter K, but I'm not sure. Anyone know?
While the original Octopus animation was never used AFAIK after about the second season, the letter animation in question was used for many years after. Hearing those notes always reminded me of a vague, distant memory of that song, which I finally got to hear again when Noggin first came along.