Corey Feldman -- Sorry, Steven Tyler ... This Is Gonna Hurt (VIDEO)

Sing for the laughter, sing for the tears ... is exactly what Corey Feldman did during a recent karaoke sesh in Hollywood -- and we got the painful footage.

Corey hit up Whiskey Blu Wednesday, where anyone -- even Corey -- can sing karaoke with a live band. He opted to jam out on the Aerosmith classic, "Dream On."

We'll say this for Feldman ... he brought some energy to the stage -- and even dared to attempt Steven Tyler's legendary scream.