They took Grandmaster Caz’s rhymes without giving him credit. Now, he’s getting revenge.

NEW YORK — Grandmaster Caz, clutching a mic as the bus rambles toward Harlem, remembers when he and his buddies decided to act. It was the late 1970s and disco had taken over. Patti LaBelle. Teddy Pendergrass. Even the Four Tops had switched to sequins and syncopated beats.

“But the straw that broke the camel’s back?” Caz tells the tourists who have paid $75 each for the roughly three-hour tour. “I saw an album cover with the ‘Godfather of Soul,’ James Brown, in a Spandex, glitter suit. I knew right there then that disco had to die. And so we hatched a plot to kill it. And it worked. That plot is called hip-hop.”

It’s Thursday and Caz, as he does three days a week, is leading Hush Hip Hop’s “birthplace” bus tour. He doesn’t own the company. A former legal secretary named Debra Harris started Hush. But for Caz, the bus is more than a gig. It’s a chance to tell his story, meet people and even perform. Truth is, he just might be the most overqualified tour guide in a city packed with them. Imagine Willie Mays pounding his glove as he walks you through Cooperstown, or Jasper Johns roaming MOMA with his docent’s badge. The difference is that Caz isn’t famous. He’s been name-dropped by Jay Z, guested on Macklemore and Ryan Lewis’s 2015 hit “Downtown,” and wrote a chunk of the Sugarhill Gang’s revolutionary smash “Rapper’s Delight.” But for reasons as old school as a Kangol, he’s got less name recognition than Vanilla Ice.