In the famous opera scene in Pretty Woman, Julia Roberts asks Richard Gere how she’s supposed to know what’s happening onstage if everyone’s singing in Italian. “Oh, you’ll know,” he replies. “Believe me, you’ll understand. The music’s very powerful.” I’ve always scoffed at the pre-supertitle cliché that if a performance is good enough you can follow an opera plot without understanding the text. Balderdash. But at Saturday’s opening of the Lyric Opera’s La Traviata,soprano Mary Dunleavy so completely wrapped herself in the character of Violetta that I found myself pondering Gere’s words once again. Her gestures, interactions, expressions — detailed yet sweeping, inviting yet tear-wrenching — were so deft that they did convey the text, to the point where I found myself ignoring the supertitles. Dunleavy, a veteran of this role in houses that include the Metropolitan Opera, sang with distinguished vocal craft and a chocolaty tone that only at times grew jarring at the top.

She was the centerpiece of the well-organized production at the Lyric Theatre, which featured stage direction by locally based Lyric newcomer Kathleen Smith Belcher. (She is, among other things, a member of the Met’s directing staff.) Her sure hand was immediately apparent in Act 1, as Violetta moved with animation at times but sparingly during quiet moments, as in her duet with Alfredo. Only the lame antics at Flora’s party in Act 2 misfired, particularly the aimless way the guy with the bull’s head moshed around crowd. Belcher’s notion of making the first two acts a product of Alfredo’s memory might remind Lyric regulars of Thaddeus Strassberger’s controversial Aida here in 2007, in which Radames dreams practically the whole opera. In this case, Alfredo wanders about the stage aprons as each act begins, gazing through the scrim as if to say “It seems like only yesterday…” It might be time for directors to think twice before jumping onto this bandwagon: It was not really offensive here, but it did little to advance Verdi’s and Piave’s delicate sense of forward-motion.

The cast varied in quality and impact, to the extent that one was sometimes reminded of the old “instant opera” formula, where a company would hire a diva to sing “her” Violetta and then just build a production around it. Tenor Chad Shelton is a fine singing actor with a deep understanding of Alfredo’s motivations: This was apparent in moments large (his electric body language with Violetta) and small (his little scoffing gestures in Act 2 that suggest he finds Violetta’s passionate love for him a bit quaint). His voice starting at about an F can take on a pleasantly heroic quality, but on Saturday the mid-range sounded gray and one-dimensional, and by Act 3 his fatigued high range was growing increasingly coarse. Baritone Lester Lynch’s Giorgio Germont got off to an odd start, with overly deliberate physical gestures and wooden articulation, but by the end he’d grown more convincing. His voice has warmth but not a lot of variety, yet he was able to imbue the portrayal with pathos.

The production featured an attractive, ingenious stage design that Peter Dean Beck originally created for Edmonton Opera. Five tall window panels with mirrored glass can be tilted downward (as in Act 1) to afford a double perspective on the action. (There were also times they allowed a good view of conductor Ward Holmquist, busy at work in the orchestra pit — an interesting bit of stagecraft that was perhaps not devoid of psychological meaning.) The panels could also be rearranged and moved downstage to create a more claustrophobic effect, as in Act 2, Scene 1. By Act 3 only three panels were left, as the heroine’s life grew more “dim.” When Annina (Violetta’s maid) tilted the center window to get a bit of air, instead it let in the tormenting sounds of Carnival revelers on the street.

Holmquist had the Kansas City Symphony strings playing with tenderness in the overture and in the haunting interludes, but when singers were onstage the ensemble was all over the map — not just the ensemble between singers and orchestra but that among the singers onstage as well. I often have the sense that performers can’t hear each other in this disaster of a theater, but on Saturday I also had to wonder if anyone was actually watching the conductor’s noticeably large and vigorous gestures.

La Traviata runs through March 22, at the Lyric Theatre. For tickets call 816-471-7344 or go towww.kcopera.org.

To reach Paul Horsley, send email to phorsley@sbcglobal.net.