The arrival of Show Boat at the Washington National Opera this month, after stops in Chicago and Houston, has provoked a certain amount of consternation in operatic circles. Does Jerome Kern and Oscar Hammerstein’s 1927 musical properly belong in the opera house, and should a precious slot in an opera company’s season be devoted to such popular and obviously commercial entertainment? Do the moneylenders need to be driven out of the temple?

The production’s director, Francesca Zambello, is well known, and sometimes criticized, for her Broadway spectacular approach to staging opera. Zambello’s first and only foray into directing on the Great White Way in 2008, Disney’s Little Mermaid, was itself a garish, incomprehensible fiasco. This staging of Show Boat, which first debuted at the Lyric Opera of Chicago last year, represents something of a hybrid approach: busy, naturalistic, and often frenetic, if not nearly as over-produced and desperate to please as a typical Broadway venture.

Thankfully, the production is also eminently respectful of the source material and displays first-rate musical values. From the pit, conductor John DeMain enforces an unfussy, lyrical approach to the score and draws polished musical performances from his singers. Indeed, the very question of the proper milieu of Show Boat is almost beside the point, as the commercial realities of Broadway today cannot match the resources and production values on display at the Kennedy Center Opera House: a 100-member cast, a full symphonic orchestra, playing Robert Russell Bennett’s original orchestrations, and most, though not all, of the singers performing without amplification.

Zambello has judiciously trimmed the book and dispensed with some of the show’s most outdated cornball humor. (One should note that the most explosive of racial epithets has been excised from the lyrics and only remains in the dialogue of the more unsympathetic characters.) The set, designed by Peter Davison, with its large-scale, if somewhat minimalist, representation of the Cotton Blossom and its use of outsized painted flats, makes an imposing, though rather vacuous, impression. Paul Tazewell’s attractive and often ostentatious costumes evoke decades of Americana, if not always serving the production’s overall naturalistic aesthetic. The choreography, by Michele Lynch, is bright and energetic but also at times unfocused and generic.

Yet for all of the evident care lavished on the score and the cleverly straightforward production concept, this Show Boat only fitfully comes to life. Zambello achieves a swift, cinematic flow between scenes, which suits the telescoped writing for Act II, yet too many scenes themselves remain stilted and weighed down by a libretto that does not match the emotional and dramatic power of the songs. More crucially, for all of the production’s musical polish, only a few performances truly plumb the depths of a show that ought to overwhelm with its staggering emotional power.

In the central roles of Gaylord Ravenal and Magnolia Hawks, Michael Todd Simpson and Andriana Churchman have precious little chemistry, denying the evening a crucial emotional through-line and blunting the epic scope of the storytelling. Simpson possesses an elegant, mellifluous baritone yet is a dramatic blank, lacking his character’s rakish charm. Churchman, meanwhile, appears ill-suited for the youthful naïveté of Magnolia in Act I and only fully comes to life in her character’s more sophisticated, resourceful, and world-weary incarnation in Act II.

Soloman Howard, one of the WNO’s Domingo-Cafritz Young Artists, displays the abundant promise of his firm, dark-hued bass as the stevedore Joe. Yet a precipitous drop-off in power in Howard’s upper register keeps the show’s central number, “Ol’ Man River”, from achieving its truly galvanic effect. It is a merely good performance of a song that demands greatness.

As Joe’s wife Queenie, Angela Renée Simpson powerfully evokes a strong sense of melancholy and foreboding in “Mis’ry’s Comin’ Aroun’.” Lara Teeter and Cindy Gold, as Captain Andy and Parthy Hawks, bring much-needed comic energy and charm to the proceedings, even if their characterizations verge on cartoonish.

Only the luminous soprano Alyson Cambridge captures the emotional heart of the show in her beautifully realized portrayal of the doomed Julie LaVerne. Cambridge brings to “Can’t Help Loving Dat Man” both a bluesy warmth and a playful sense of romanticism. And in the second act, the evening reaches its high point in Cambridge’s poignant, vulnerable, and ultimately heartbreaking rendition of “Bill”, a performance that aches with longing and despair. It is a doubly painful experience, as it all too briefly reveals the full emotional potential of this granddaddy of American musicals and points the way to what might have been.