The Gong Show
Synopsis
People who thought they had an entertaining talent did their act, but could be kicked off at any time by the sounding of a gong. Those who weren't gonged off were given marks by a panel of judges and whoever scored highest was declared the winner.
The original US version of The Gong Show hosted by Chuck Barris was one of Channel 4's early hits, being shown twice weekly, but for some reason this UK version never made it past the pilot stage.