The legendary announcer was eliminated off Fox's "The Masked Singer" this week ... and as it turns out, the dude can sing pretty well!!
Buck -- who lasted 2 episodes -- put on an impressive rendition of "I Want You to Want Me" by Cheap Trick to start off his experience ... but no one knew it was him at the time.
But fans finally got to meet the man behind the mask on Wednesday ... and it turned out to be none other than one of the most famous voices of the NFL and MLB.
