Green’s Dictionary of Slang

(US black) foolish talk, prattle, nonsense.

1969		J. Crumley One to Count Cadence (1987) 190: He grinned widely and said, his bop-talk gone, his accent heavy [etc.].
1980		E. Folb Runnin’ Down Some Lines 230: bop Thoughtless or foolish talk.
1999		J. Ridley Love Is a Racket 318: Unlike the others she’d turned away quick, this one she let work his bop for a while.