There is great merit in an opera that exists for sheer pleasure. An opera whose music washes over you, bathes you in sweet melody while it amplifies the emotional quotient. An opera without much of a plot that manages with supple ease to carry you away; yes, to make you sympathize with paper-thin characters who you wish would make better choices and live a happy-ever-after life, although you're fully aware of the inevitability of the tragedy that will unfold.

Loosely based on Goethe's classic epistolary novel The Sorrows of Young Werther, Jules Massenet's Werther (German world premiere 1892, French premiere 1893) is slight in the extreme. Librettists Blau. Milliet and Hartman pared the book down to its core. Politics is out, social satire is out, his wanderings through Europe out. They keep the unconsummated love plot. And Massenet runs with it brilliantly.

Moody romantic Werther falls for young innocent Charlotte, who's engaged to stuffy Albert. Werther will not be dissuaded, but Charlotte, at first, is unshakable in her devotion to her dying mother's wish. At Charlotte's insistence, besotted Werther goes away for half a year, only to return at Christmas eve. His passion is feverish, his desire unrequited. In desperation for never having her, he commits suicide with Albert's hunting pistol. Unlike the novel, Charlotte discovers him dying, declares her love, and finally kisses him while he dies in her arms. Very sad, indeed.

French film director Benois Jacquot botches even this simple plot by having Charlotte plant a big wet one on Werther in Act III, giving herself away before the Act IV reveal in Werther's bloody garret. Jacquot is partially responsible for the hideous sets in Acts I and II (although credited to Charles Edwards) and the unchangeable costumes for all the characters. Time passes, but nobody wears different clothes. It must be symbolic. Act I is sparse in spades – cyclopean walls and immense gate out of King Kong, a dusty vine crawling on the brick wall, and no hint of the bucolic country farm that Werther apotheosizes in his glorious aria to nature, “O, nature, pleine de grâce” (“Oh, nature, filled with charm.”) He's blind in love, for certain, but physically blind?

Act II fares no better. Supposedly placed in the town square with church and lime trees, whose relevance will become apparent at opera's conclusion, this rustic German village is rendered by a diagonal black swath of fabric slicing across the horizon. We're in Expressionism land, angled like the Cabinet of Dr. Caligari. None of this makes dramatic sense, and is ugly to boot. When the curtain rises on Act III, Charlotte and Albert's drawing room, we breathe a relaxed sigh – finally a room to live in, plain but functional with a window stage left to wash the set in late December light. Unfortunately, everyone enters the room from the wings, neglecting the impressive double doors center stage. Where's the director? Act IV, Werther's garret, lumbers impressively from upstage to stage edge as snow falls in the background. It's a most satisfying conclusion to a muddled concept.

What isn't muddled in the slightest is Massenet's sinuous music, what could be described as the musical epitome of Belle Epoque, curlicued and sensual, detailed and visceral. The score is beautiful in the extreme and deeply satisfying. Although suicide for love is the primary theme, Massenet overlays the darkness with sparkling rhythms, gossamer orchestration, and utterly graceful melodic lines. There's plenty of sturm und drang during Werther's and Charlotte's emotional outbursts (Charlotte's “Letter Scene” remains a competition showpiece), but even though filled with anguish and unfulfilled desire, the whole is elegantly presented and most expressive music making. There are strikingly original orchestral interludes throughout, miniature tone paintings just as important to the story as the arias. These little sparklers light up the opera, deepen it.

Massenet was blessed with an unfailing knack in pleasing his audience. He gave them what they wanted – melodies to hum and a pleasant evening at the opera house. He wrote in all styles: grand historic spectacle like Meyerbeer, Le Cid; love potions and magic à la Wagner, Esclarmonde; religious erotica, Thaïs; demimonde scandal, Manon (his abiding classic); comedy, Chérubin; fairy tale, Cendrillon; literary adaptation, Don Quichotte. He was France's most successful and famous composer. Until he wasn't. His grace and style went out of fashion during his career, and most of his work faded into obscurity upon his death in 1912. In an unfair slam, he was ridiculed as “the daughter of Gounod.” Like all forgotten masters, he was rediscovered in the latter half of the 20th century when singers like Sills, Sutherland, Domingo, Kraus, von Stade realized the musical gold mine Massenet could provide them. Massenet wrote star parts for star singers.

Werther is a gem, glittering when dark and foreboding, perhaps even more scintillating when so, and polished with effervescence in its unerring, unending melody. Houston Grand Opera, who last produced this work 45 years ago, has found perfect leads in international superstars tenor Matthew Polenzani and mezzo Isabel Leonard. Ideal interpreters of this unique French style of lyric opera – one of manner, phrasing and beauty of tone – they breathe fresh life and intelligence into it, turning this rare beauty into exciting theater.

Polenzani supplies heft and control. His showstopping reverie, “Pourquoi me reveille” (“Why wake me”) is a dream come true, while Leonard gives Charlotte startling phrasing, radiance and plummy sound. Exceptional interpreters in song, they happen to be very good actors also, which is what Massenet demands since the action is purified into repressed emotion. Perhaps this is the area where director Jacquot shines. Someone brought out the not-so-subtle shimmering these two express when together. These characters get it. These singers get it. The audience gets it.

The subsidiary characters might be drawn with pencil, but their music is fitting and rich. Buzzy happy sister Sophie (soprano Jasmine Habersham) is bright coloratura; town drunks Johann and Schmidt (bass Cory McGee and tenor Ricardo Garcia) are comic foils besotted with character song; suspicious Albert (baritone Sean Michael Plumb) has menacing undertones swirling in the orchestra; while Charlotte's father, the Bailiff (bass Patrick Carfizzi) plays doting dad surrounded by his children learning Christmas carols in July.

Grammy-winning maestro Robert Spano, currently music director of the Fort Worth Symphony Orchestra, leads the HGO orchestra with an alluring and lively French accent. He gets Massenet, too.

Jules Massenet always gave his audience a good show. He didn't invent anything new in technique or fashion, but used whatever was happening in contemporary music to suit his particular purpose. Werther is a small opera, intimate and domestic, but its message is universal and its music encompasses the world. It's a stunner, well worthy of discovery.

Werther continues at 2 p.m. Sunday, January 29; 7:30 p.m. Saturday, February 4; 7:30 p.m. Wednesday, February 8; 7:30 p.m. Friday, February 10 at the Wortham Theater Center, 501 Texas. Sung in French with surtitles. For more information, call 713-228-6737 or visit huostongrandopera.org. $20-$210.