I recall the song from the movie soundtrack being played on AM radio a bunch when I was a kid in the 60s. Wikipedia sez “Sesame Street producer Joan Ganz Cooney heard the track on the radio and decided it would be a perfect addition to the show.”
It made it as high as 55 on the Billboard Hot 100.
Sole reason people can accept ‘manometer’ as a humidity meter. Wait, maybe that’s not it…density meter? Nope, dry or wet air pressure. Wasn’t there a longer word?