Those dancing horses, as well as their music video, are pleasant and happy. The chorus of "Janitor" actually has an interesting story behind it.
From Wikipedia:
The lyrics of "Janitor" were derived from a real-life conversation between Sue McLane and friend Brian Smith. According to Brian, the two were conversing in a loud room when they first met:
"She asked me what I did for a living. I said 'I'm a janitor,' and she thought I said 'Oh my genitals.' [Richard Whitney] overheard this and wrote the song."
And that voice. Have you ever heard such a voice? I can't help but laughing every time I hear her say "Who's your mother, who's your father?"