When DJ Kool Herc threw his back-to-school party at 1520 Sedgwick Avenue in August 1973, "It's Just Begun" was already in heavy rotation. The Jimmy Castor Bunch had released the track a year earlier as part of their self-titled album, and its relentless groove — built on a locking drum pattern and stabbing horn figures — made it an immediate favorite on New York dancefloors. For the emerging b-boy culture, the extended drum break was a playground. Herc would loop it back and forth between two copies, stretching those four bars into an eternity of motion.

The break's influence on early hip-hop is difficult to overstate. Afrika Bambaataa paired it with "Apache" at Bronx River jams, Run-DMC built "Sucker M.C.'s" on its rhythmic DNA, and Mantronix used it to bridge the gap between old-school breaks and electro-funk. When Mobb Deep flipped it for "Shook Ones Pt. II" in 1995, they proved the break could carry the weight of something far darker and more introspective than the party music it was born into.

Jimmy Castor himself was a Harlem-raised multi-instrumentalist who moved between doo-wop, Latin soul, and funk with an easy versatility. "It's Just Begun" captured him at his funkiest, and the track's endurance as a hip-hop source record far outlasted the chart success of the original single. It remains one of the foundational documents of breakbeat culture.