Over the past decade, Boston Ballet has been nothing if not ambitious. The ghosts of the company’s big new productions haunt the wings of the Wang Theatre: Carmen, Dracula, Cleopatra, The Hunchback of Notre Dame. None has been seen on stage since its initial appearance, and none is likely to be; they’re in a permanent chrysalis state. The company’s latest undertaking, Stanton Welch’s Madame Butterfly, doesn’t blaze over the boards like a monarch or a tiger swallowtail — it’s more like a delicate, pale-green luna moth. But it’s Boston Ballet’s best new offering since 1994’s Onegin, and opening weekend it was stupendously danced. I’ll be looking forward to its return visits.

This Butterfly’s shortcomings are largely those of the Puccini opera on whose story and music it’s based. The tale of a Nagasaki geisha who " marries " an American Naval officer and then is deserted by him is negligee-thin next to the plot of Onegin (which Boston Ballet will be bringing back in October), and Pinkerton and Butterfly are Scarpia and Tosca all over again: brutal, self-serving man; noble, victimized woman. I wonder, too, whether this ballet’s plot will be comprehensible to those who aren’t familiar with the opera. Some second-act details slip by, like what Pinkerton writes in his letter to American consul Sharpless, and the fact that after three years’ absence he’s still paying the rent for Butterfly’s house. It’s hardly clear why marriage broker Goro goes on so about Butterfly’s son, and the most chilling (or maybe it’s just the most perverse) moment in the opera is lost, when Butterfly tells Kate that Pinkerton can have Sorrow if he comes for the boy in a half-hour (he’ll discover Butterfly’s corpse). Perhaps the ballet needed more room to spread its wings: it flits by in just 80 minutes, as opposed to the opera’s 140.

In many respects, however, 32-year-old Australian choreographer Stanton Welch has improved on Puccini. To the music of Pinkerton’s " Yankee vagabondo " aria (which is framed by quotations from " The Star-Spangled Banner " ), Sharpless hands him a letter, and we see, in a flashback to a party scene that Edith Wharton or Henry James would recognize, that it’s from Kate and that she’s already his lady friend. This innovation establishes Kate as a real and engaging person (but does it make Pinkerton’s " marriage " to Butterfly the more reprehensible in that he already has an American girl?), and she remains so when she reappears at the end: upon discovering that her husband is the father of Butterfly’s child, she expresses her displeasure with him in no uncertain terms.

Pinkerton is hardly softened early on. He’s equally casual about Kate’s letter and Butterfly’s photo; at the beginning of the marriage ceremony Sharpless has to pull him down to his knees; after Butterfly has warmed the wedding bowl of sake with her hands, he chugs it; and he downs two more bowls while she’s changing out of her wedding dress. Yet he lifts her tenderly from the ground after the intrusion of the Bonze, and when she emerges from the cocoon of that dress, he’s all hers in the melting pas de deux that Welch has created for the end of act one. The moustache he sports at the end of act two suggests that he’s matured, but it’s too late. Welch’s American consul Sharpless is Pinkerton’s foil, being more attentive and sensitive to Butterfly and Suzuki and even a little in love with them. And Welch’s Suzuki transcends her servant-girl status: after catching Pinkerton’s eye early, she looks wistfully on when Butterfly signs the marriage contract.

Welch’s choreography is simple and elegant; it’s not the steps you remember but the way he uses them. For the act-one duet between Pinkerton and Sharpless, he creates a brief pas de deux in canon, Pinkerton dancing with Kate’s letter in his hand, Sharpless with Butterfly’s photo; it’s echoed in the second-act canonic pas de deux for Butterfly, who’s full of faith, and Suzuki, who’s full of despair, that he sets to " Un bel dí vedremo. " Toward the end there’s another bit of choreographic counterpoint when Pinkerton tries to make his case to Kate and Sharpless does the same with Suzuki, both men relying on power rather than poetry. His advances rejected by Kate, Suzuki, and Sharpless in turn, Pinkerton is reduced to solipsistic pirouettes.

Then there are Welch’s stunning setpieces. I never figured out what the opening tableau — Butterfly behind a cherry-blossom scrim is lifted aloft by an unseen force — is supposed to mean, and Butterfly’s subsequent emergence out of dry-ice clouds had me wondering whether the wedding had been moved to Las Vegas. But Welch makes exquisite use of Puccini’s " Humming Song, " first in a sequence when Butterfly is going through the motions with rich suitor Prince Yamadori and Pinkerton, in his undershirt, drifts on upstage, as if in a dream, to dance with her, and then by having Suzuki and Butterfly and Sorrow wait for Pinkerton behind screens where Suzuki and Butterfly, black silhouettes in an orange light, do a dance with fans that’s as ethereal as Puccini’s pizzicato strings and as yearning as the melody he layers on top of them.

What follows in the opera is an orchestral passage drawn from the first-act love duet, Butterfly thinking of Pinkerton as she sits up all night. Welch visualizes this music as " The Americanization of Cio-Cio San, " wherein Butterfly dreams that Pinkerton, again in his undershirt, has returned, they dance rapturously, she’s in America, foolish American ladies are fussing over her, accepting her (Puccini’s morning birdsong is ingeniously turned into the chattering of caged canaries), then Pinkerton brings in Sorrow, they’re all about to sail to America, but Butterfly’s way is blocked by four ronin (from the Loyal 47?), specters of her desertion and ultimate bushido-inspired suicide. (Throughout all this there’s a discreet sprinkle of cherry blossoms from above, in homage to the request of Puccini’s heroine that cherry blossoms might rain down upon her.) As for the big pas de deux for Butterfly and Pinkerton, it’s no virtuoso showpiece but an emotionally focused series of long phrases with hardly any transitions (I kept getting flashes of Balanchine) that describe arcs of feeling, Pinkerton throwing her out but then pulling her back in. It ends with the lovers couched under the stars, Puccini’s chiming melody played with sublime magic — as is the rest of the score — by Jonathan McPhee and the Boston Ballet Orchestra (the better you know the opera, the more you’ll appreciate how good their performance is).

What’s most enlightening about this Butterfly is the way Welch’s detail facilitates different characterizations. Larissa Ponomarenko’s Cio-Cio San is an Utamaro beauty (or maybe the great Kurosawa and Mizoguchi actress Machiko Kyo) come to life, breathtaking in her stylization and obsessive in her belief in Pinkerton. Adriana Suárez is more sensual, more down-to-earth, even maternal, not so lost in her own world. Pollyana Ribeiro is fairy-tale regal, as if she were marrying the Japanese crown prince; when at the end Viktor Plotnikov’s Sharpless tries to give her money, she stares him off with a look that would freeze fire.

Yury Yanowsky’s Pinkerton is a dark Heathcliff type, somewhere between Gene Kelly and Stanley Kowalski (when after the wedding guests had left he pulled off his shirt, I expected to hear someone yell, " Stella! " ); his pas de deux with Ponomarenko has the most flow and speed. Simon Ball is Pinkerton as Tom Cruise or Matt Damon, a ROTC lieutenant from a fine family and a fine school, perhaps just a bit spoilt, with a rougher edge than I expected (Matt as Tom Ripley?), and very emotional in the finale. Paul Thrussell is the Robert Redford/Richard Gere golden boy of the trio, very spoilt, but even as he’s paying out more money to Goro, he can’t take his eyes off Ribeiro’s Butterfly, and he’s iconic in his heart of darkness (heart of emptiness?) when he stands with his back to us, spread-legged, waiting for her to emerge in her wedding-night dress. Yet she transforms him into her fairy-tale prince: the look on his face says, " Who’s Kate? " Their pas de deux at the Saturday matinee reduced me to tears: some things transcend critical explanation.

Thrussell pushes Welch’s envelope even farther as Sharpless. Cast opposite Yanowsky’s Pinkerton, he’s the not-at-all ugly American who treats Suzuki with respect and can’t stop looking at Butterfly’s photo; if this production were a Hollywood movie, he’d latch onto Sorrow, tell Pinkerton and Kate to vamoose, marry Butterfly himself, and find Suzuki a loving husband. The stiffness of his little split jumps with Pinkerton’s letter bespeaks his frustration and helplessness. Viktor Plotnikov is a more conventional (which is not to say worse), almost British Sharpless, concerned rather than involved. Pollyana Ribeiro is his Suzuki in a sisterly, sensitive portrait that’s unexceptionable. Jennifer Gelfand’s portrayal draws more attention to itself; her Suzuki is bursting with playfulness and high spirits and just waiting to be discovered. For a dancer who started out as all virtuoso and no personality, Gelfand has gone from caterpillar to butterfly; I wish we could have seen her as Cio-Cio San. Sarah Lamb offers a dignified, almost aristocratic version that’s winsome against Plotnikov’s Sharpless. Welch’s Kates are less distinctive: April Ball, Sabine Chaland, and Karla Kovatch are all effective in the same general way, mostly sympathetic (the way Kate tosses Suzuki her hat does have " servant " written all over it) but very American with the tight-curled blond wig. I started out wishing this character could have been sweeter and less artificial, but over the course of one dress rehearsal and three performances last weekend I realized that she represents part of Pinkerton’s mindset, that they belong together in a hard-to-understand way that he and Cio-Cio San don’t. That’s the tragedy (as opposed to the melodrama) of Madame Butterfly, and it’s something that Welch understands at least as well as Puccini.

A brief postscript: it’s easy for the critic who’s getting free seats to pontificate about how edifying it is to see different casts. But back in March this critic plunked down $70 to watch Tara Hench in Balanchine’s Slaughter on Tenth Avenue one more time — and when the curtain came down, I felt I’d got my money’s worth. Then Jennifer Gelfand came on as the Cowgirl in Rodeo and I decided I’d underpaid for my seat. So if I ask you to put your money where my mouth is, that’s because my money’s there too.

PHOTO BY ERIC ANTONIOU