Casting causes some problems for venerable ‘Man of La Mancha.’

Call it the Niche Theory of L.A. theater.

So vast and varied are the types of small, medium and large theaters spread across town that it seems that when one operation takes its last bow, another emerges to take its place. If a vacuum is created in a niche once filled by some daring, dead company, it almost immediately gets filled.

The replacement is never quite the same, and it is, well, quixotic to expect something to come along and replace the defunct California Music Theatre, which specialized in staging rare revivals like “Strike Up the Band” and “On the Town.” But just when CMT goes belly up, along comes the Civic Light Opera of South Bay Cities. Its first show, in fact, was very much in the CMT ballpark--a revival of the seldom-seen “Mame.”

Its second show is something else again--a revival of the oft-seen “Man of La Mancha.” (CMT did its own revival two years ago.) Chances are, though, that unless South Bay audiences trekked up to Hollywood earlier this year to see the almost universally reviled Raul Julia-Sheena Easton version, they haven’t seen Dale Wasserman’s fanciful adaptation of Miguel de Cervantes’ novel “Don Quixote.”

So CLO of South Bay Cities is actually filling two niches at the same time and, at this point, doing a fair job of it. Apparently, the city of Redondo Beach thinks so too: Managing Director James Blackman announced Sunday night that the city, which owns the Aviation Park auditorium where the company is housed, is pouring $1.4 million of capital improvements into the facility.

It’s a deserving act of good faith, since Teri Ralston’s staging handsomely makes the most of the theater’s limited physical plant. With designers Liz Stillwell (lights) and Robert Bingham (set), Ralston has created a Spanish Inquisition dungeon and Quixote’s imagined world with real conviction on a short budget.

Ralston, a stalwart of South Coast Repertory, also knows something about actors, and you sometimes wish she would have made different decisions about her cast.

It revolves around Noel Harrison as Cervantes/Quixote, and that’s part of the problem. Harrison takes a while to get revved up--his Cervantes is utterly flat--and his limited voice can’t handle all the dimensions of the Mitch Leigh-Joe Darion score. But having recently performed Jacques Brel songs in intimate venues, Harrison has brought some of Brel’s dramatically harsh, gutsy edge to “La Mancha.” Though he rushes through “The Impossible Dream,” (musical director Irv Kimber keeps his good orchestra steady throughout), Harrison lends much of the material a human desperation that climaxes in the death bed scene. The Knight of the Woeful Countenance, indeed.

Some actors, such as Frank Lee White as the Padre, seem to have been chosen for their singing voices; when White speaks, you wonder if he’s not a Padre of the San Diego baseball variety. David Dollase’s Duke/Carrasco is all stolid sternness, while Rudy Tronto’s Sancho is all show biz.

Jonelle Allen’s Aldonza, on the other hand, is all business. She maneuvers this woman’s trek from cold bitterness to unleashed idealism with abandon, and lends the production the air of well-earned romanticism, representing goodness gained through considerable hard knocks. Allen gamely gets treated like a sack of potatoes at points, but, like the show, can stand up straight at the end.

What: “Man of La Mancha,” Civic Light Opera of South Bay Cities.

Where: Aviation Park Auditorium, Aviation and Manhattan Beach boulevards, Redondo Beach.

When: Today, 8 p.m.; Saturday-Sunday, 2 and 8 p.m.

Admission: $15.50-$35.

Information: (310) 372-4477