https://www.youtube.com/watch?v=qwfYTZqpGTg
Want to see two members of Spinal Tap before they were Spinal Tap? Harry Shearer and Michael McKean first became acquainted in the late 1960s when they joined a satirical comedy group called The Credibility Gap, who were known for delivering comedic commentary on Los Angeles radio stations. The Credibility Gap performed on radio for several years, but Shearer and McKean got some of their first television exposure when the group did a spoof of Tom Snyder’s talk show, The Tomorrow Show, and were actually invited to perform the sketch on the real Tomorrow Show.