By Ralph Novak
September 22, 1986 12:00 PM

Here’s something for the morbidly curious among pop music fans. Among the 60 minutes of ’60s and ’70s TV performance clips are Helen Reddy doing a hilariously bad job of lip-synching I Don’t Know How to Love Him, Shirley Bassey overacting wildly on Diamonds Are Forever, Neil Diamond trying to appear funky while doing Cherry, Cherry and the Osmond Brothers on One Bad Apple, offering a truly pale imitation of the Jacksons. Other performers include Billy Joe Royal, Mickey Newbury, Harpers Bizarre and Wayne Newton. The only really affecting clip is by John Denver, who seems to be performing Leaving on a Jet Plane live (he sings with only his own guitar accompaniment) and with uncommon emotion. (The Video Late Show, no suggested price)