You don’t need to be a fervent theater fan to get excited about lost musicals from the creators of “Fiddler on the Roof” and “Cabaret.”

And you can thank Steve Young, a longtime writer for the “Late Show with David Letterman,” for unearthing these works — industrial musicals, which corporations would put on internally, featuring big names like Sheldon Harnick and Jerry Bock (“Fiddler”) and John Kander and Fred Ebb (“Cabaret”), not to mention stars such as Florence Henderson (in a show for Oldsmobile dealers).

“There are quite a number of famous names who worked in industrials because it was excellent money and it was excellent practice for your craft,” Young says. “You had people like Hal Linden and Valerie Harper — all these great up-and-coming performers — who found that industrials were a wonderful way to pay the rent, meet people and improve your skills. And I think they were treated quite well. They would go out on the road or whatever and be put up in good hotels. It actually paid better to be doing industrials than real Broadway shows, unless you were a star on Broadway.”

Young, who wrote on more than 1,500 episodes of the Letterman show, has turned his work on a segment from that series into a book, an upcoming documentary, a feature film currently in the works and a live show, “The Lost World of Industrial Musicals,” which is coming to the Alamo Drafthouse in Brooklyn on Thursday.

“One of my duties as a writer back in the ’90s was to round up the raw material for a bit we did called Dave’s Record Collection, which consisted of Dave holding up real, unintentionally funny record albums,” Young says. “And we’d hear a little sample and we’d have a joke.”

But it was Young who was out scouring used record shops for albums to feature, and he started finding these souvenir records from company events, which had featured, he says, “full-fledged, extremely elaborate musicals.” The shows would be performed at conventions or sales meetings and printed in small amounts for the people coming to the events.

But now, finally, the general audience can experience these musicals.

“You couldn’t go into them as an audience member, you couldn’t buy the record in a record store,” Young explains. “This was all completely off the grid as far as the public was concerned.”

As he came across more and more of them, he realized that this was sort of a musical genre, which led to his book, “Everything’s Coming Up Profits: The Golden Age of Industrial Musicals,” written with his friend and fellow collector Sport Murphy.

At Thursday’s event, Young will be playing rare footage from industrial musicals, such as “The Bathrooms Are Coming!” and “Got to Investigate Silicones,” as well as playing some of the songs and discussing their significance.

And yes, he does acknowledge how strange and kitschy these works are.

“You think, ‘This is crazy that there are musicals about selling tires and selling typewriters or light bulbs — it just seems insane,’” he says. “And then you dig a little deeper and you realize it made perfect sense at the time and place.”

And despite the topics, Young says that some of the shows are of high quality.

“Not all of them were good — in fact many of them were somewhere between mediocre and bad,” he says. “[But] there were enough that were unbelievably good with A-list talent that really just leaned into it fully and said, ‘If we’re going to do a show about lawn mowers, then it’s going to be the best show about lawn mowers that anyone could do.’”