Richard Pryor and Steve Martin talk on The Tonight Show in June of 1978. It’s rare to see people actually conversing on talk shows today. It’s usually over-rehearsed bits, which are especially obvious when the guest is a stand-up comic. You can trace the shift in format to David Letterman, who never seemed comfortable in interviews and often looked like he wished he was anywhere else.
Guest hosts are also rarer now. Jay Leno takes few vacations, and Letterman and the rest just throw on a repeat. I believe the last instance of high-profile guest hosts on a talk show was when Letterman had heart surgery.
The new material that Pryor says he’s “woodshedding” would become his double album Wanted and film Live in Concert.