Scary scene at the Fatman Scoop concert … after he passed out onstage and got CPR according to eyewitnesses … and TMZ has it all on video.

The legendary hip hop hype man was performing Friday at Town Center Park in Hamden, CT when he appeared to suffer a medical emergency.

Folks who were there say Fatman Scoop collapsed and passed out … with people rushing over to administer CPR. Authorities tell us they were dispatched for a medical emergency at 8:33 PM.

The music suddenly stops and a hush falls over the crowd … and you hear murmurs about Fatman Scoop getting CPR.

The person who took this video says they saw Fatman Scoop fall over … and he was ultimately taken out on a stretcher.

Unclear what may have caused this whole thing … but hopefully Fatman pulls through.

Fatman Scoop’s worked with a ton of big names in hip hop over the years … collabing with the likes of Missy Elliott, Mariah Carey and Jermaine Dupri … just to name a few.

We reached out to Fatman Scoop’s camp … so far no word back.