This movie was about krump -- a subtype of hiphop dancing -- that originated in South Central, Los Angeles. The first part tells us about Tommy the Clown, who does birthday parties and has inspired lots of followers. Some of the followers broke off and now not only consider themselves the starters of krump, but that it's in them from birth. This is where there's a long segment alternating krump dancing with archival African films. This is stupid -- there's also a short bit where the guys are krumping and a toddler is waving his arms like the big boys -- that's where it comes from.
Some things about krump: it's faster than hiphop (but the people who were really fast were never in rhythm), it's used to get your anger out (it would be better if they didn't have all-day anger), the girls/women only get to krump for a few minutes during an all-day krumping (women are second-class), and a lot of krumpers clearly lie (film evidence).
It's hard to think of any good things about krump -- I'd much rather the guys look for jobs that provide them with income so they're much less angry and teach their children to be less angry.