The songs, which have creaky titles like “All that razz” and “Hooray for What's-not-good,” are belted out with pitchy gusto.
I take Escobar at his word that this was basically locker-room talk—a joke, meant to razz other players.
"to hiss or deride," 1920, shortened and altered variant of raspberry (q.v.) in its rhyming slang sense. Related: Razzed; razzing. As a noun, in to give the razz, from 1919.
To insult and ridicule; needle, ride: Is there ever any razzing about the fact that you report to your wife?
[1920+; fr raspberry; found in the form razoo by 1890]