Unquestionably, Kaufman's premise is strong. He's imagined musicologist Katherine Brandt (Fonda) becoming transfixed by Ludwig van Beethoven's exquisite "Diabelli Variations" and then determined to get to the bottom of their germination by examining the composer's sketches now housed in a Bonn archive. To add to the situation, Brandt -- who has a tense relationship with daughter Clara (Samantha Mathis) -- hopes to complete her study on the subject before succumbing to a rapidly advancing case of amyotrophic lateral sclerosis (also known as Lou Gehrig's Disease).
To complicate matters further, Kaufman introduces both an attending nurse, Mike (Colin Hanks) with an increasing yen for Clara, and archivist Gertrude Ladenburger (Susan Kellermann), whom Brandt befriends as she goes about gathering data to support her thesis about Beethoven's intentions.
But the conniving Kaufman doesn't stop there. He throws into the mix the growling, wild-haired, hearing-impaired Beethoven (Zach Grenier), as well as the master's long-suffering factotum and early biographer Anton Schindler (Erik Steele) and music publisher Anton Diabelli (Don Amendolia), who penned the unpretentious waltz that catches both Beethoven's and Brandt's fancies. That's a lot of ingredients for one play -- without even mentioning the Steinway piano just below stage level on which nimble-fingered Diane Walsh regularly plays either Diabelli's modest opus or snippets of what Beethoven so astonishingly did with them.
Kaufman juggles these elements in ways that are sometimes rewarding and convincing -- particularly in the mother-daughter reconciliation that slowly unfolds -- and sometimes not. For example, Kaufman's depiction of Beethoven can be excessively along what-a-bombastic-cuss-he-was lines. Moreover, Kaufman not only equates to the point of incipient dyspepsia the composer's eventual deafness with Brandt's illness; but in a couple sequences, the characters in the present and those in the past mouth the same sentiments in unison (or shall we say in variations). It's a theatrical conceit that cheapens rather than enriches the work.
Although he stumbles in the writing, Kaufman makes no noticeable slips in a stunning production that's designed by Derek McLane to include archive stacks on casters and is enhanced by Jeff Sugg's projections of sheet music with replicas of Beethoven's writings. As for the cast, Fonda -- in her first Broadway appearance in over 45 years -- does a reputable job of growing progressively infirm; Grenier is the Beethoven that Kaufman wants; and Mathis and Hanks fall sweetly in love. Indeed, the entire ensemble sees to it that verbal music is made with the literal music.