With Super 8mm film and some lucky "wild sound" lip synching....
...a homemade kinescope!...
It was a warm summer in 1974, and the shredded lettuce at Burger Chef tasted so sweet...like the sweet taste of shredded Watergate documents...the sound came a few months later when a magnetic stripe was added to the original super 8mm film and the whole thing recorded on the fly, complete with projector noise. Back when you could still do six impossible things before breakfast...