When Steve Young was tasked with picking up vinyl oddities in thrift stores, swap meets and record meets, the kind of obscure albums that could make for great punchlines for a segment on the “Late Show with David Letterman,” where he was a writer for over 25 years, called “Dave’s Record Collection,” it’s likely the same notion floated through his head about himself as it did when he first got his hands on his first recording of an industrial musical: “This must be the strangest dead end in show business.” However, for the professional joker who had become immune to more traditional forms of comedy having heard it all before, Young quickly became enamored of some of the strangest yet most delightful albums he found – Broadway-style musicals that were intended for private use at corporate events aimed at boosting employee morale and impressing clients by incorporating company messaging into irresistible song-and-dance numbers.

It turns out that the musicals, often penned and performed by tried-and-true theater professionals making a living while working towards their Broadway aspirations, still retain their zest and you might find yourself unconsciously humming, “Everything’s Coming Up Citgo,” as you leave Dava Whisenant’s infectious “Bathtubs Over Broadway,” but just as undeniable is the appeal of Young’s personal story as his journey to track down every one of the rare corporate souvenir albums that companies distributed as keepsakes of their big productions gives him a sense of purpose as he approaches middle age. Set against the final days of the “Late Show,” the wildly entertaining documentary has considerable gravitas to go with its steady stream of crowdpleasing musical numbers, unearthing rare footage from such productions as “Lipton on the Move” and “The Bathtubs Are Coming,” an ode to plumbing fixtures that becomes a particular obsession of Young’s.

Young isn’t alone in his pursuit of material from these live events that could cost more to stage than an actual Broadway production, and a sense of community is formed with fellow collectors, musicians such as Jello Biafra and Don Bolles, who playfully tease him for outbidding them on eBay for albums that only had one or two copies made at most for historical purposes. However, “Bathtubs Over Broadway” really takes off when Young starts connecting the dots between productions to find out who worked on what musicals, a process that puts him in touch with such famous performers such as Chita Rivera and Martin Short, who secured a steady income in industrial musicals, but lesser known craftspeople including composers Sid Siegel and Hank Beebe, who appear to be overjoyed to have shows that they put the same amount of work into as any other piece of art to finally have it recognized.

While Young isn’t one to call attention to himself naturally, Whisenant cleverly draws a parallel between the platform he’s giving to others by elevating him to movie star status, turning his enthusiasm into charisma and allowing his unbridled passion for songs such as the “Detroit Diesel Dazzle” become the big, beating heart of the film. Also, in her capacity as the film’s editor, she keeps “Bathtubs Over Broadway” as diverting as any good show, creating a lively history of the industrial musical, both with Young as the best tour guide you could have and first-person accounts with those who lived it, as well as an insightful profile of a man whose singular obsession leads to something far bigger than himself. Like Young, “Bathtubs Over Broadway” takes something so obscure and makes it feel so big and as much as the film’s star insists throughout that “none of this should’ve happened,” given how shrouded in mystery the industrial musicals seem at first, you’re not only so happy that it has, but that it’s filled with as much charm, wit and ingenuity as what Young fell in love with in the first place.

“Bathtubs Over Broadway” will play at the Tribeca Film Festival on April 28th at 4 pm at the Cinepolis Chelsea 9 and April 29th at 1:45 pm and 6:45 pm at the Cinepolis Chelsea 2. It will next play at Hot Docs in Toronto on May 1st at the Hart House at 9:30 pm, May 3rd at the TIFF Bell Lightbox at 9 pm and May 5th at 3:45 pm at the Isabel Bader. A full list of upcoming screenings is here.