The story
Imitative, representing the sounds of the bass drum and snare drum, respectively.
Etymology from Wiktionary, CC BY-SA 4.0.
boom bap
Today it means: A style/subgenre of hip hop characterized by hard-hitting drums, usually containing the kick drum/snare drum/hi-hat combination rather than claps, snaps, TR-808 bass drums, cowbells, shakers, and various other percussion sounds used for rhythm. Full definition →