Dennis Rodman put in WORK on the streets of Vegas Monday night ... teaming up with a bucket drummer outside Planet Hollywood ... and the people loved it!
We're told it all went down around 10 PM ... when Rodman was walking around the strip and saw the dude murdering the bucket drums.
Rodman grabbed the mic and busted out James Brown's "Get On Up" ... and it wasn't bad.
Shout-out to the guy in the background trying to put down one of those giant slushy drinks from Fat Tuesday. Enjoy the hangover, pal.