Swing For My Supper (1941) - Dorothy Dandridge 

If you mean Betty Boop, no, that was about a decade earlier and, was Mae Quetzel, though based on Helen Kane....

Yup! Very likely this was the first time it was used in this context.

There was a hit song in 1934 actually called "Rock and Roll" so, not really.

The 1934 song titled “Rock And Roll” was sung in a film by the Boswell Sisters, and was also recorded by them too. The lyrics are about trying to dance while on a moving cruise ship: “Rock & roll, roll and rock away / Up and down, round and round we’ll sway / With each tide, as we glide / To the rollin’ rockin’ rhythm of the sea…” The clip from the film as well as the recorded version are both on RU-vid.

@@hebneh Wow, fascinating origin info. Too, thank you for the tip to it on RU-vid.

He acts in a few other of her soundies, e.g., bongo drums in "Jig in the Jungle."