What’s the difference between hip-hop and hardcore hip-hop? In the late-Reagan/early-crack years, you could make that distinction best with BDP’s South Bronx-hewn debut full-length, one of the era’s great prototypes for both East Coast gangsta rap and intellectual-beatdown lyricism. KRS-One started a long peak here as the educated revolutionary who battled all comers, and the team of the late DJ Scott La Rock and (an undercredited) Ced-Gee helm early-sample-era beats that dictionary-define “boom bap.”