Four people squabble over whether Beethoven intended a "poco crescendo" in measure 16. If he had, wouldn't he have written it in? Not necessarily; it's open to interpretation. No, it's not; yes, it is. Let's flip a coin.

Welcome to the sausage factory of classical music. In "Opus," playwright Michael Hollinger reveals the ordinary humanness of musicians engaged in exquisite art. They snipe in jealous rage, fumble through early-morning haze and chatter about last night's ballgame (at least they're Yankees fans, so they usually have something to cheer about).

Hollinger's play, a slight but thoroughly enjoyable sliver of the rare life, opened Friday at Park Square Theatre in St. Paul. Director Mary Finnerty's production, articulated on Michael Hoover's spare conceptual set, might not strike each note precisely, but the drama breathes with emotion and narrative -- the greater accomplishment.

"String quartets are like a marriage, but with more fidelity," says Elliot, the prickly first violinist played by Paul de Cordova. His relationship with mercurial violist Dorian (Peter Christian Hansen) has cratered and as the play opens, the gifted Grace (Emily Gunyou Halaas) auditions to take Dorian's place. The stakes are high: the "Lazara Quartet" has a fast-approaching White House engagement.

Scenes alternate between rehearsals that reveal the messy details of four people trying to make beautiful music, and flashbacks that illustrate how Dorian and Elliot's personal tension got us to this point. The other two musicians, Alan (David Mann) and Carl (Stephen D'Ambrose), are easygoing chums who try to keep the personalities on an even keel. It's not easy.

There is lots of chewy stuff in Hollinger's play. Hansen shows the fragile personality of a genius who knows he should have been first violin but whose mental health relegated him to viola. Alan, fully aware of Dorian's brilliance, explains to Grace that, "You don't want Joan of Arc leading you. You might want her alongside you, but not leading." Dorian's relationship with the brittle Elliot illustrates how personal passion poisons the professional relationship.

Beyond this, the simple candid details of preparation provide steady entertainment. Elliot turns up his nose at the idea of playing Pachelbel's Canon for the president. "It sounds like a tampon commercial," he sniffs. They argue over strident lyric lines and E-flats that aren't sharp. The actors mime with their instruments to music recorded in C. Andrew Mayer's sound design.

In his quest to make something more of this glimpse, Hollinger reaches for a dramatic conclusion that feels elliptical in the way a TV show might introduce a smoking gun that comes out of nowhere in the last five minutes of the episode. Tense histrionics argue in favor of the moment, even if it's a twisty trick. You should decide for yourself, because the play is worth the trip.

Graydon Royce • 612-673-7299