Goethe once defined a string quartet as “a discourse among four reasonable people,” and in a good performance, that’s certainly the way it sounds.

But discord is common in quartets, and while second violinist Alan (Jeffrey Bender) says “At its best, it’s like a marriage only with more fidelity,” volatile violist Dorian (Mark H. Dold) counters with “At its worst, it’s like swallowing Drano.”

Right now, the fictional Lazara String Quartet is in a time crunch: days away from an important gig at the White House, it is auditioning recent graduate Grace (Katie Sigismund) to replace the brilliant but “buggy” Dorian (Mark H. Dold), fired by headstrong first violinist Elliot (Jim Abele) for his erratic behavior.

Creativity, artistic temperament and personal quirks collide in Michael Hollinger’s Opus, onstage in a riveting Old Globe production through April 26 at the San Diego Museum of Art’s Copley Auditorium. UCSD theater professor Kyle Donnelly directs.

Hollinger knows musicians: an ex-rocker, he trained as a violist at the Oberlin Conservatory. Fortunately for us, he has found his forte in playwriting.

Hollinger gives us a complex group of distinct personalities: Elliot the acid-tongued drama queen; Alan the charming lothario; Carl the laid-back family man; the mercurial but brilliant Dorian; and timid newcomer Grace, who just wants a regular job so she can defend her choice of a music career to her doubting family.

I suppose Opus could be faulted for its heightened, almost soap opera-like characters and situations, a melodramatic ending, and the occasional unhelpful intrusion of a TV camera for an interview, but overshadowing these is the considerable joy of watching artists at work. In the Beethoven Opus 131, for example, Alan questions Elliot’s interpretation of the marking “ma non troppo.”

“I know what ‘ma non troppo’ means,” snaps Elliot.

“Well, that was clearly troppo,” Alan retorts. “It sounds like we’re smothering a baby.”

It’s a tribute to sound designer Lindsay Jones that the actors, who bow but do not finger their instruments, almost convince us they are playing the recorded music from the sound booth.

There is no real set; the actors move four folding chairs as needed. Donnelly intelligently plays into the in-the-round stage configuration by changing the seating order each time the quartet sits down to play, and a large TV screen on each theater wall adds another viewing possibility.

These actors may not be musicians, but they understand the concept of ensemble performance. Each contributes to and takes what’s needed from the whole. It’s a lovely piece of work all around.

The joy and sorrow of live music is that it is recreated anew every performance, but gone forever as soon as the music dies – much like an actor’s performance. Opus is a fascinating glimpse into the life of those who are lucky enough to make a living creating music.

Opus plays through Sunday, April 26, at San Diego Museum of Art’s James S. Copley Auditorium. Shows are Sunday, Tuesday and Wednesday at 7 p.m.; Thursday through Saturday at 8 p.m.; matinées Saturday and Sunday at 2 p.m.

For tickets call 619-23-GLOBE or visit www.theoldglobe.org.

Romance, mistaken identities, contract murder and a selection of goofy antique collectors converge in The Hit, playing an open-ended run on Lamb’s Players’ mainland stage at the Horton Grand Theatre. Robert Smyth directs.

The company’s multitalented resident set designer Mike Buckley is practically a one-man show here, serving as playwright, set designer, props man and actor.

On the wonderfully cluttered antique-shop set, Cynthia Gerber plays Susan Timmerman, who runs the San Francisco shop with younger brother Steve (Chris Bresky), a community college math whiz pondering an offer to tutor math at Stanford. He wants to go, but is reluctant to leave Susan to run the shop alone.

Susan, recently diagnosed with cervical cancer, is secretly planning to have herself whacked by a hit man and leave everything to Steve. She is awaiting the arrival of the – how to say it? – contractor.

Enter unsuspecting neighbor Sam (Buckley), not to be confused with contractor Samm (Season Duffy), the latter carrying on the family tradition of gun for hire. Romantic sparks are ignited between Sam and Susan, leading to predictably amusing cross-purpose conversations and other goofiness.

Meanwhile, Steve and Samm hit it off – especially verbally, as they waltz around the shop punning on the motley merchandise. But Samm understands the complications of mixing work and pleasure, leading to more misunderstandings and hilarity. You know how this will end, but no matter: getting there is all the fun.

Bresky’s energetic, romantically shy and totally lovable geek Steve is a great foil for Duffy’s outgoing Samm, with her colorful multicollege educational background (sans degree), outlandish outfits and, shall we say, unusual profession.

Gerber is great in her emotional roller-coaster of a role that has her falling hard and fast for Sam and immediately backing away when she contemplates the “arrangement” which will leave this once-widowed guy alone again.

Paul Maley and Kerry Meads play a memorable assortment of oddball antique collectors, from Maley’s silent, automaton-like observer to the dreaded woman who comes in a few minutes before closing, picks up everything and buys nothing.

The Hit played on the company’s Coronado stage in 2008 and was so well-received that Lamb’s has moved it across the bay where it can run as long as there is demand. This delightfully frothy concoction may run forever – and should become a staple on the regional theater circuit as well. But don’t wait. The Hit is too much fun.

Lamb’s Players Theatre’s production of The Hit is in an open run at the Horton Grand Theatre. Shows are Thursday at 7:30, Friday and Saturday at 4 and 8 p.m.; Sunday at 2 p.m. For tickets, call 619-437-0600 or visit www.lambsplayers.org.