Ceasar F. Barajas (Pedro), Amber Iman (Aldonza), JP Moraga (Tenorio), James Hayden Rodriguez (Jose) and Nathan Lucrezio (Anselmo) in Shakespeare Theatre Company’s production of “Man of La Mancha.” (Scott Suchman)

When Anthony Warlow squares up and sings the title song in “Man of La Mancha,” you won’t find many people in Sidney Harman Hall complaining that the 1965 musical about fighting unbeatable foes is schmaltz. Ditto for Amber Iman’s hot-tempered, full-throated turn as Aldonza, the salty serving wench and prostitute romanticized as an elegant lady by the idealistic Don Quixote. The singing is so sumptuous and the acting so passionate that any argument is squelched. Performing well is the best revenge.

If the Shakespeare Theatre Company’s musicals are going to be this good — and this is only the second they’ve fully produced at Harman Hall — they may as well keep a hand in the game. The classical rationale for “La Mancha” is that Miguel de Cervantes and Shakespeare were contemporaries and that “Don Quixote,” the inspiration for “La Mancha,” is a cornerstone of Western literature. But there’s another justification: Artistic director Michael Kahn has always set the bar high for performance on his stages, and his young protégé, “La Mancha” director and STC associate artistic director Alan Paul, upholds that standard here.

The charismatic Warlow leads the charge in one of those cases when a role just flat-out fits. Warlow’s silky baritone unwinds in long, confident phrases that shower the chivalric “Dulcinea” with tender romanticism and makes “The Impossible Dream” rewardingly heroic. He also plainly relishes playing the whimsical Cervantes of writer Dale Wasserman’s imagination, jailed during the Inquisition and playacting fables with the roughneck inmates sharing his dungeon.

As if worried that skeptics will find the uplifting “La Mancha” too sweet, Paul — director of last season’s popular “A Funny Thing Happened on the Way to the Forum” at the STC — makes this 16th-century Spanish prison as loud and as grim as he can. Allen Moyer’s set is a towering iron-barred cube featuring a catwalk high above the stage, with the ensemble (in terrific rustic period costumes by Ann Hould-Ward) trapped below. The prisoners yelp and bang and generally make a madhouse of the place, and while a little of this goes a long way, it’s also the unavoidable violent insanity that Cervantes both inhabits and civilizes.

Aldonza gets the worst of the mayhem, of course, given that she has to endure not just leers but gropes and thrusts and the famous rape sequence (children are warned away in the company’s advertising). Iman lets all this inform her dauntingly tough performance; she takes Aldonza’s numbers slowly, which injects a good deal of drama and sounds like an embattled woman trying to take some measure of control. She also has a vocal overdrive gear when she needs it; the modern bluesy edge to Iman’s singing works just fine, and her defiant showdowns with Warlow’s persistent knight have a wonderful undercurrent of curiosity.

An 11-piece orchestra led by music director George Fulginiti-Shakar is tucked away on the balcony level to one side of the stage, and this is the galloping, ballad-rich Mitch Leigh-Joe Darion score as you expect it — guitars and winds and horns, Broadway sentiment laced with Spanish flair. The pushback is that this is (yawn) yet another mid-20th century American musical, a seam worked to bits lately at Arena Stage and all over town. (Nehal Joshi’s clowning here as the sidekick Sancho will be familiar to audiences who saw him in Arena’s “Oklahoma!” as the comic peddler Ali Hakim.) Thank heavens for the daring new projects lately at the Kennedy Center and the reliably adventurous Signature Theatre — oh, wait, Signature’s doing “Cabaret” in May, and the Olney Theatre Center’s “Carousel” starts next month . . .

None of that is Paul’s problem. There is muscle in “La Mancha,” and he flexes it with a balanced, sturdy-voiced ensemble boasting “Les Miserables” in their bios instead of the usual Shakespearean credits. The consistent solid singing and respectful seriousness — along with the fascinating way Warlow’s magnetic centerpiece performance seems to get under the steely Iman’s skin — gives this “La Mancha” authority to dream big.

‘Man of La Mancha’

Book by Dale Wasserman, lyrics by Joe Darion, composed by Mitch Leigh. Directed by Alan Paul. Choreography, Marcos Santana; lights, Robert Wierzel; sound design, Ken Travis; fight choreographer, David Leong. With Dan Sharkey, Rayanne Gonzales, Robert Mammana, Martin Sola, Ceasar F. Barajas, Nathan Lucrezio, Sidney DuPont, JP Moraga, Joey Elrose, James Hayden Rodriguez, Maria Failla, James Konicek, Jay Adriel and Ethan Watermeier. About an hour and 50 minutes. Through April 26 at Sidney Harman Hall, 610 F St. NW. Tickets $20-$115, subject to change. Call 202-547-1122 or visit www.shakespearetheatre.org.