The Doobie Brothers have played to countless crowds over the years, but one of their most memorable gigs got its start on Jan. 28, 1978, when the band tried to do a nice thing for some high school students and ended up being bootlegged by a kid wearing a trench coat and a beret.

We're talking, of course, about the Doobies' two-part appearance on the ABC sitcom 'What's Happening!!,' in which viewers discover that the band just happened to graduate from the Watts high school the show's characters attended, and they decide to give a concert on campus -- but then the ever-bumbling Rerun (played by Fred Berry) ends up being strong-armed into secretly recording the gig.

The Doobies were far from the only musical act to put in an appearance on a prime-time series during the '70s (who can forget the time Davy Jones showed up on 'The Brady Bunch'?), and no one tuned into these episodes for the acting; as you can see in the clips above and below, no one was working on an Emmy reel. But it's become a cult favorite over the years, and something the band good-naturedly celebrated with a Throwback Thursday tweet on Jan. 28, 2015.

Joking that it's "the thing we’ll always be remembered for, probably," Doobies co-founder Patrick Simmons recalled years later, "It was just a lot of fun. We got to know the people from the TV show and enjoyed the whole experience of a situation comedy."

Unfortunately, the two clips we have here leave out the climactic conclusion of the second episode, in which Rerun's gigantic '70s portable tape recorder is exposed, setting in motion a scene in which, as Mental Floss put it, "The band, who are so upstanding they named themselves after an illegal drug, proceed to lecture the youngsters on morality and righteousness." Sure, there are unofficial uploads on YouTube, but at the risk of getting caught like poor Rerun, we'll stick with the authorized stuff. Get your 'What's Happening!!' Doobies fix at the top of the post and down below.