Prince’s set on this week’s “Saturday Night Live” will be unusual. He’s worked out an 8 minute jam session for the show. This will be the longest anyone’s ever played on “SNL.” I’m sure he’ll feature material from his two new albums, but if he’s smart–and he is– Prince will bookend his medley or whatever with “1999” and “Let’s Go Crazy” or some hits that will click with the audience. I’ve been at sets where he doesn’t do that, and it’s kind of draining. This week’s host is Chris Rock, who asked for Prince, they say in a press release. Chris will be promoting his “Top Five” movie that’s coming out shortly, with the amazing Rosario Dawson.