I don’t remember it in the Birthday song from my childhood but I heard it a lot, though not always (maybe 40%), when I started working children’s parties in the mid-90’s.
But, I’m sure it started further back, and I don’t think it had to have had a single source (like a popular children’s show). Kids just LOVE “Cha Cha Cha’s”!
What I do remember from my childhood is the Chipmunk’s Christmas Album.
We like girls all kinds of girls
From Annie to Veronica
We like them short or fat or tall
I want to play my Harmonica!
Throughout the song Alvin inserts several pleas that he be allowed to play his Harmonica. This gets David very annoyed and he shouts: “ALVIN!” several times.
Finally David breaks down and allows Alvin to play Harmonica at the end of the song. At the end of each line of the melody of Alvin’s Harmonica solo, Simon and Theodore sing their little “Cha Cha Cha’s”- this infuriates David, who attributes this disrespectful behavior on Simon and Theodore’s behalf to Alvin’s bad influence.
He tries to scold them but they continue the song, paying him no notice. In the fade-out a frustrated David laments “It was supposed to be a sweet song, and now you’ve got them dancing and ‘Cha Cha-ing’!”
As kids, my siblings and I thought this was hilarious! From the “Cha Cha’s” all the way through David’s frustrated rant. We saw the “Cha Cha’s” as a wonderfully irreverent addition in which youth asserts it’s presence and identity in the face of “old-fogey-ism”.
I imagine the “Cha Cha’s” will always hold such power and fascination for young children. Basically, they think it’s fun and they know the adults think it’s weird- this makes it all the more special.
It’s basically the kids’ version of this guy ->