first of all, it started off as a Party thang at Parliament / funkadelic concerts in LA in the 70’s, yellin’ out “Whoop! whoop!” at concerts.

Then it became a Denver Lane Bloods homie call… like “what up!”… (as far as it being recorded, 1994 is the earliest i’ve found, with G-Len’s album “woop! woop!”) it also means you’re jackin’ someone, woopin’ woopin’! ya know, woopin’ on a niggaz ass, woop a niggas ass! woop! woop!

obviously I.C.P. got their own thing wid it… Shaggy on stomp, and the rest is juggalo history… you know the rest

if anyone can correct me on this please do… peace!