33 Variations, at the Purple Rose, is about the beauty of intellectual engagement. Its two central characters feel their value to the human race is so crucial, and their time so short, that they bumble and crash through their human relationships–even as they deftly execute their work. The title refers to one of Beethoven’s last compositions, which took on an obsessional quality in the twilight of his life. We see the composer himself on one part of the stage; on another, a contemporary musicologist races to complete her study of the Variations before her own life ends.

Moises Kaufman (The Laramie Project) recapped the variations of the title in the play’s thirty-three short scenes. Or so I’m told–most flow into each other, creating what feels like a conventional two-act play. In this Purple Rose production, rhythm and harmony undergird every moment, particularly pleasing in a play that is literally about rhythm and harmony.

Katherine Brandt (Michelle Mountain), the musicologist, is a fictional creation, but she’s investigating an actual conundrum: why did Beethoven write thirty-three variations on a simple, popular waltz of the era? Like any good story about an intellectual quest, the real heavy lifting is explaining not so much the answer as why anyone would ask the question in the first place. I came home enlightened.

I’m not sure how cutely numerological Kaufman was trying to be, or to what end, but since he went to the trouble to package the play itself into 33 scenes, he must have been conscious that threes–triplets and triads–thrum throughout 33 Variations. The play dances between its two sets of characters–a triad composed of Beethoven and two of his contemporaries, mirrored by a present-day triad of Brandt and her comtemporaries. And another strange numerological echo occurs when Brandt’s circle expands to four–around the time she makes a breakthrough in her search to discover why Beethoven’s first variation switches from a swaying, danceable 3/4 waltz to a more solid, and stolid, 4/4 march.

Without those intellectual explorations, 33 Variations would be just another fatal-disease melodrama. It sure walks the rim of that canyon, at the bottom of which lie any number of made-for-TV movies where a beautiful woman has inexplicably tense and unhappy relationships with the perfectly nice people who surround her, only to resolve them in a snuffling deathbed scene. That happens here. Brandt has a disease; I won’t give away what it is, though it is revealed early on. But the disease theme by itself isn’t very strong or original.

I loved Vincent Mountain’s set–an archive of high metal shelves neatly filled with all the weird boxes and receptacles that knowledge is stored in. Rhiannon Ragland reprises her excellent German accent from Boeing-Boeing a few years back, playing a stiff scholar who becomes a friend. Richard McWilliams makes a nimble, impish Beethoven. All in all, it’s a good, smart production.

33 Variations runs through June 1.