In 1819, Ludwig van Beethoven was middle-aged, almost broke, nearly deaf, and suffering a mid-career cold streak. When music publisher Anton Diabelli asked him to remix a middling beer-hall waltz Diabelli had composed as the basis for an all-star compilation volume, Beethoven first refused, then changed his mind. Over the next three-odd years, the Maestro was intermittently obsessed with Diabelli’s tossed-off little ditty, creating not one, not two, but yes, three-and-thirty variations on a piece he had initially — apparently — thought unworthy of his attention.

Why he did this is the mystery at the center of 33 Variations, a world-premiere from Moises Kaufman, he of the great Gross Indecency: The Three Trials of Oscar Wilde and the ubiquitous The Laramie Project. But whereas those plays were assembled from the testimonies of real people, often quoting their sources verbatim and at length, this is more of a conjectural work derived from Beethoven’s musical sketches and a small number of his conversation books that survive from the era.

Not that this is purely a period piece. In fact, it takes Beethoven himself, nicely played by Graeme Malcolm in full Christopher-Lloyd-as-Doc-Brown mode, 25 minutes to show up. While we’re waiting, we get the beginnings of a parallel story, set in the present day, of a musicologist’s (Mary Beth Peil) journey to Beethoven’s archives in Bonn to figure out for herself why he’d been so consumed by such a seemingly minor project. (He was composing his Ninth Symphony — the immortal work of genius without which the Home Alone trailer, and perhaps Macaulay Culkin’s entire career, would never have been possible — during roughly the same period.)

Katharine, the musicologist, is dying of course — there needs to be some urgency to the proceedings, right? — and while her daughter (Laura Odeh) wants her to come home and prepare for the inevitable, Mom’s having none of it.

Wait, it’s better than it sounds. The sources of conflict in Kaufman’s script may be familiar — Mom vs. mortality, daughter vs. Mom’s expectations, daughter vs. the Central Casting nice guy (an underused Greg Keller) whose overtures she resists for all the phony rom-com reasons, etc. But as with the titular variations, it’s the inventive recasting of unremarkable material that gives this production, which Kaufman also directed, its considerable charge.