"Your eyes will be opened to a world full of beauty, charm, and adventure," my fortune cookie predicted, and the prediction came true even before the curtain went up on the Boston Early Music Festival’s sparkling new production of Johann Georg Conradi’s Die schšne and getreue Ariadne ("The beautiful and faithful Ariadne"). BEMF’s centerpiece opera reopened the refurbished Cutler Majestic (formerly Emerson Majestic) Theatre, and everything from the lobby to the sanitary facilities has been reconfigured and improved. The second balcony, with its precipitous incline, has been reopened, and this intimate theater glitters with old-fashioned elegance. It’s perfect for Baroque opera, and part of the pleasure of the production was being in that theater.

Conradi was both a composer and the music director of an important opera house in Hamburg, which gave special attention to the work of Lully. He died in 1699, and what is now his only surviving opera was last produced in 1725. The score disappeared before it was rediscovered in the Library of Congress in 1970. It’s a kind of missing link between Monteverdi, a century earlier, and bel canto (Bellini, Donizetti) a century later. It’s also an important precursor of the entire German operatic tradition. Many plot elements (though few musical ones) foreshadow Mozart’s greatest work in German, Die Zauberflšte ("The magic flute"), which ends the 18th century: magic bells, a trio of ladies, and a comic coward who’s afraid to enter a labyrinth. In 1912, Richard Strauss rehearsed the same myth in Ariadne auf Naxos. Co-music director, lutanist Paul O’Dette, writes that Conradi’s music combines Italian-style arias, French orchestral passages (including the dance music), German folksongs, and the accompanied recitatives of German Passions. Plotty and moralizing, the opera deals with Theseus’s betrayal of Ariadne, using her help to extricate himself from the labyrinth so that he can run off with her sister, Phaedra. Theseus was a popular subject — this was BEMF’s third opera about him.

Much of the music for Ariadne herself expresses "pathetic" or violent emotions, but the most charming music comes in various ensembles, especially trios (rather than duets). A bawdy knife-sharpener song, hilariously delivered by German tenor Jan Kobow as Pamphilius, Theseus’s Papageno-like servant in green kilts and tam-o’-shanter, is followed by an extended chorus and dance that ends the first act with raucous double-entendres ("whoever doesn’t get his scissors sharpened now will have to spend the rest of his life with very blunt ones"). There’s even a Brechtian moral: "Whoever can’t grind others must himself be ground." The punch line comes when the shortest dancer reveals that he is endowed with the longest blade.

The second act has the least compelling music, though the third remedies the drought with a spectacular aria for Ariadne that reverses the later bel-canto tradition by beginning with the cabaletta (the fast section with brilliant coloratura) and ending with the slow cavatina. Canadian soprano Karina Gauvin, whose glowing voice, consistency of pitch, superb German diction, and emotional focus remained impressive from her opening aria on, blew the lid off with bravura singing that Cecilia Bartoli could envy.

Canadian countertenor Matthew White, as Bacchus disguised as Evanthes, one of Ariadne’s suitors, has a firm, warm sound, though he was less convincing as the powerful god of wine and revelry than as the pleading suitor. The others, including Boston’s Ellen Hargis as both Pasiphae and Venus, were more variable, especially concerning pitch and timbre. The duets between the stiff Theseus (tenor Ian Honeyman) and the manic Phaedra (soprano Dorothee Mields) made me yearn to hear more of Gauvin.

Physically, this was the handsomest of the biennial BEMF operas. Robin Linklater’s flats receding in perspective, and ornate costumes and headgear, were lavish without being gaudy. Once again, Lucy Graham’s choreography emphasized energy and wit over pinkies-out preciosity. I was about to give up on Drew Minter as a stage director last summer (he’s still best known as a countertenor) when in Opera Aperta’s Don Giovanni he had the Don lick the blood of the Commendatore, whom he had just stabbed in a duel. But here Minter’s blocking was more restrained, flexible, and focused. I still resist BEMF’s insistence on Baroque textbook posing. For awhile, Minter’s singers looked as if they were semaphores or were playing charades — using hands and fingers to mime every word. Eventually, this irritating artificiality disappeared — and it wasn’t missed.

One operatic clichŽ Minter would do well to avoid is the device of having characters mime conversations while others are singing. This time, it was Bacchus having a little chat with Ariadne during the finale. It’s bad enough when an opera is trying to be realistic, but a god pretending to be just one of the guys looks silly.

O’Dette and codirector and fellow lutanist Stephen Stubbs led the superlative 30-piece orchestra, seated in a circle at the foot of the stage, in some very stylish yet gutsy playing. I hope later performances eliminate the little pauses between musical numbers — tiny dead spots that interfered with the overall continuity. (Ariadne moves June 20 through 22 to the Mahaiwe Performing Arts Center, in Great Barrington.)

WILLIAM CHRISTIE’S Les Arts Florissants has a very different approach to Baroque opera. Instead of just trying to re-create what a performance looked like in the 18th century, he tries to locate the elements that are still vital to us. The Brooklyn Academy of Music has just imported Christie’s new Paris Opera production of Rameau’s posthumous "lyric tragedy" Les Boréades ("the followers of Boreas," god of the north wind), the master’s last work, which went into rehearsal in 1764 but was never actually produced until 1982. The impulse to see it right after Ariadne was irresistible.

Christie gathered an amazing team of artists. I’d put Canadian stage director Robert Carsen high on the small list of great stage directors currently working. Les BorŽades had some of the most haunting and spectacularly gorgeous stage images I’ve ever seen. Michael Levine designed the spare but deeply dimensional sets and illuminating, sometimes ominous costumes, all in blacks and whites, like the clothing in Patrice Chereau’s memorable Wagner Ring Cycle, a combination of Victorian and contemporary dress. And undress — characters removing or putting on garments took on a major symbolic role (though in Brooklyn, evidently unlike Paris, there was no nudity). Pater van Praet and Carsen himself produced the thrilling lighting effects.

Unlike Conradi, Rameau is a very great composer. While Ariadne remains essentially a love story based on a famous myth, Les BorŽades takes on deeper issues. The argument is about whether Love is a path to freedom or another trap. It’s also a profound nature myth, humanized by its human characters. Love is a life force, a force of nature and light, and the moving human story is an exemplum of how nature works.

Queen Alphise must marry a descendant of Boreas, and two of his offspring are vying for her hand. But her heart chooses someone else, of mysterious origins (who turns out to be the son of Apollo and a "nymph of Borean blood"). In his rage, Boreas makes the seasons change and brings devastation. Summer — depicted by the entire stage covered in an ankle-deep meadow of technicolor flowers — gives way to autumn, and the falling of thousands of red, orange, gold, and brown leaves. Mysterious dark figures cross the stage holding upside-down open umbrellas by their tips and twirling them so more leaves keep swirling out. The storms get worse. Snow comes out of the clouds — and out of the twirling umbrellas. And finally, when love wins, there is light (even the house lights come up), the flowers are replanted, and rain pours down. This time the umbrellas are right-side up, offering comfort, protection, and renewal.

In a marvelous wedding banquet scene, a stage-filling square white table is set against a horizon of a black sky glittering with uncountable stars. Guests march in, each holding up a gleaming knife and fork. At the heart of this work is deep suffering ("thorns lurk beneath the flowers"). And real heroism — as Abaris, Alphise’s true love, risks everything to save her, with the help of an arrow bestowed upon him by the young, blind Eros (who uses that arrow as a cane to feel his way). Carsen’s indelible images all mirror the storms and sunlight in the music. Everything means something.

Even the overture began with horns and other winds playing from the side boxes — like an old map in which the four winds are blowing "at the round earth’s imagin’d corners." The music is sublime — maybe most sublime in the cascading phrases in which Abaris uses Love’s magic arrow to awaken the fallen lovers. It’s one of the most heavenly passages in all of opera. The dance music ranges from the formal to the exuberantly comic (as when the rain descends at the end). Christie led the amazing players with unstoppable momentum over nearly four hours.

Christie’s singing actors don’t often get the credit they deserve. They’re willing to sacrifice the "perfection" of tonal glamour to express most fully their emotional states. In Paris, soprano Barbara Bonney sang Alphise; in New York it was French-born Italian soprano Anna Maria Panzarella, who was heartbreaking in her full-out yet nuanced singing. Her intensity was matched by the elegant Scottish tenor Paul Agnew, as Abaris. Baritone Laurent Naouri was the angry god, tenor Toby Spence and baritone Jean-SŽbastien Bou the two Boread princes, soprano Ja‘l Azzaretti Alphise’s confidante, baritone Nicolas Rivenq the sonorous Apollo (who sang his potent last-act aria suspended high above the stage), and boy soprano Benjamin Goldsmith the sinister yet tender God of Love.

Rameau is one of the great composers of dance music. Les BorŽades, masquelike, is filled with dances. The controversial choreography by ƒdouard Lock (founder of La La La Human Steps) is like Balanchine’s Agon (a modern vision of Baroque dancing) on speed. Were these dancers or hummingbirds — their feet and arms fluttering and twitching? In Antonioni’s Blow Up, David Hemmings and Vanessa Redgrave are listening to rock music. She’s nervously trying to groove, but he tells her to relax, to move "against the beat." So she slows down, and he’s right. Lock’s flickering leaps, sudden spins, and darting scissor-kicks are "against the beat" of Rameau’s languorous beauty. Very odd, but like everything else in this profound and moving production, they also mean something; they work.