Oh, what a smart idea this is. Once a week, in prime time on Saturday nights, NBC will present a slightly truncated episode from a selected season of Saturday Night Live, That’s 40 episodes, with one selected episode per week. They’ll be shown out of order, but this new retrospective series is starting things off with a smartly selected episode from the inaugural 1975-76 season of SNL. The episode, the seventh in Season 1, features Richard Pryor as guest host, and Gil Scott-Heron, of “The Revolution Will Not Be Televised” fame, as musical guest. Best moment, which is certain to be included: Chevy Chase giving a racially tinged word-association quiz to a prospective janitorial appointee, played by Pryor. If they play it in prime time, unedited, I’ll be surprised – but pleased.