The Ultimate Breaks and Beats series, conceived by the late Bronx-based record collector and low-key DJ Lenny Roberts, played an essential role in the evolution of rap music. Its 25 volumes were released between 1986 and 1990, and empowered many a DJ and producer (very partial roll call: Jam Master Jay, Kurtis Mantronik, DJ Premier) by providing easy access to sought-after tracks that often required much time and money to hunt down. Someone with an encyclopedic knowledge of rap music could probably rattle off a series of cuts that took an element from each selection in the series, whether it's a drum break, a flute loop, a guitar scratch, a Hammond line, or a vocal snip; and if you've merely been a fan of hip-hop, odds are good that you'll be familiar with a lot of what you hear. The artwork on each installment of the series doesn't indicate the volume, but you can go by the catalog number -- SBR 501 is the first volume; SBR 502 is the second, and so on. The 21st volume features Sound Experience's "Devil With the Bust," Barry White's "I'm Gonna Love You a Little Bit More," Joe Tex's "Papa Was Too," and All the People's "Cramp Your Style."