The Boston Early Music Festival (BEMF) is now in its 11th season. Every two years, for more than two decades, scholars, instrument makers, performers, and devotees of pre-classical music have come to Boston from all over the world to meet one another, attend the concerts, and look at the displays. The centerpiece is usually the fully staged production of a neglected 17th-century opera, and this audience of specialists usually eats it up. Lately, there have been American premieres, in new performing editions by the festival’s music directors, Paul O’Dette and Stephen Stubbs. Now, after several seasons of Italian operas (Rossi, Cavalli), they’ve crossed into France for a rare go at a tragédie en musique by the Italian-born favorite of Louis XIV, Jean-Baptiste Lully, who was a dancer as well as a musician. His fourth opera, Thésée, with a libretto by Philippe Quinault, turns the story of Theseus and Medea into a glorification of the Sun King and the building of Versailles. It held the stage in France from its 1675 premiere right up to the French Revolution (which didn’t much cotton to celebrating monarchs). It hasn’t been staged since. (Thésée will be repeated at Tanglewood this weekend, June 22 and 23.)

The primary ambition of these BEMF productions seems to be the re-creation of textbook Baroque style rather than any attempt to convey drama through that style — which is what makes them seem so precious. They represent an entirely different kettle of bouillabaisse from the theatrical imagination of William Christie’s inventive productions with Les Arts Florissants.

This year, the singers, especially the women, seemed more at ease, less arch, in the gestural language. They moved smoothly, almost naturally, had good, erect posture, and didn’t seem too self-conscious. Modern men seem disproportionately tall for the elaborate costumes and wigs and so look more awkward. They always seem to be leaning. The string of BEMF stage directors, including this year’s Gilbert Blin, evidently think that dramatic action lies either in static posing or in crossing the stage a lot.

The pre-festival publicity promised “frightful ghosts, monsters, and flying dragons,” more spectacle than we got. Designer Robin Linklater’s gaping jaws of Hell looked about as scary as the entrance to a carnival chamber of horrors. At least in Lucy Graham BEMF has found a choreographer who fills the stage with graceful dances in a convincing style, and we got a company of dancers light on their feet and demonstrating, when called for, a shrewd sense of character (as in the delightfully sour comic dance for two horny old men).

The chorus was once again superb, though the solo singing this year was more variable. The audience favorite was soprano Laura Pudwell (returning after her raucous portrayals of both Bacchus and the Nurse in Rossi’s L’Orfeo, in 1997), as a scenery-chewing, violently jealous Medea. She got a bigger response from her growling and bellowing outbursts of rage than from her actual singing, but at least — unlike anyone else — she was displaying emotion (“Lethal rage, jealous delirium, I abandon myself to you”). Tenor Howard Crook sang stylishly but blandly in the title role opposite soprano Ellen Hargis’s sympathetic but pale-sounding princess. More-focused and resonant singing from Canadian bass-baritone Olivier Laquerre, as the king’s confidant, and Boston soprano Kendra Colton, in the abstract roles of a priestess and, at the end, Minerva, managed to ring through the voice-flattening, bone-dry acoustic of the Copley Theatre.

As usual, the real star was the BEMF Orchestra, under the alternating direction of Stubbs and O’Dette, with exciting work from Baroque-trumpet players John Thiessen and Alex Bonus and French percussionist Marie-Ange Petit goosing the lively military music and lutenists O’Dette and Stubbs and harpsichordist Peter Sykes providing a rippling undercurrent of rhythmic life.

Lully’s contribution to the history of French opera was the invention of a kind of fluid recitative, but Thésée is not one of his best scores. Several duets and a trio, and some of the dances, had more musical interest than the generally bloodless solos. Quinault’s relentlessly sententious text has some amusing sardonicisms (“Happy are two inconstant lovers when both are unfaithful”). Most memorable was a touching if repetitive pastoral duet for two shepherdesses on an enchanted isle (Jayne Tankersley and Megan Sharp) — non-characters, really. It was staged with solemn simplicity, with pairs of on-stage flutes and musettes (little bagpipes — portable keyboards pumped by underarm bellows). For the non-specialist, it was not a big enough payoff for three hours and 40 minutes of waiting for something inspired and ravishing.

That came the following night with the Boston debut of the extraordinary Italian gambist Paolo Pandolfo. In just the first 20 minutes of his recital with young Norwegian theorbo/Baroque-guitar player Thomas Boysen and American harpsichordist Mitzi Meyerson, there was music more beautiful, more moving, and funnier than anything in Thésée.

These sublime and characterful works were by Marin Marais (interspersed with two less satisfying interludes wherein Meyerson hammered solos by Marais’s younger contemporary and rival Antoine Forqueray). Pandolfo is committed to the idea that this music is specific and descriptive. His program notes provided his own little poetic précis for each selection (as the great French pianist Alfred Cortot used to write, with perhaps less authority, for each Chopin Prélude). Then he introduced each group of pieces to the audience.

These explanations were probably unnecessary, though they were more charming than most in-concert musical lectures because Pandolfo had such eager conviction. It was as if he were trying to counter years of applause for technique without poetry. I would have “heard” Marais’s imitations of a musette and a guitar and “seen” the parade of the Persian ambassador’s guards marching closer and closer even without Pandolfo’s descriptions, or “seen” the badminton shuttlecock sailing back and forth in the air even without his shifty eyes following it, so vivid is his playing. Perhaps most remarkable was Le tableau de l’opération de la taille, Marais’s depiction of a bladderstone operation, which Pandolfo turned into “melodrama” by declaiming the details of the surgery as he played.

And what heavenly playing! His bowing is light and elegant, but it boasts an astonishing range of colors and dynamics, with pinpoint intonation. You think he couldn’t play any softer — or faster, or slower — and then he does. In La musette, the bagpipe seemed to materialize out of thin air, then disappear into it. Nothing could be more plaintive than the sighing phrases Pandolfo brought to Plainte, or more poignant than his depiction of Marais’s son dying after a battle (Tombeau pour Marais le cadet), or more exquisite than the labyrinth of musical apparitions in Chaconne en rondeau (beginning with Meyerson’s plucked harpsichord string) — the one encore. No doubt about it, Pandolfo is a genius — the Yo-Yo Ma of the viola da gamba. I can’t wait to hear him again.

In the meantime, I’ll make do with more-familiar favorites, like pianist Russell Sherman and the Borromeo String Quartet at the splendid Rockport Chamber Music Festival, together in public (I believe) for the first time. The Borromeos are one of the rare ensembles who can play Mozart (K.387) and Bartók (Quartet No. 2) with equal conviction and profundity. They understand how Mozart’s classicism fuses grandeur with piercing intimacy, how formal perfection both withholds emotion and intensifies it. They heard in still-early Bartók modernist quizzicalness, Hungarian rhythmic assertiveness, and the melodic/harmonic contours and transparency of Debussy (who was still alive — though not for long — when Bartók completed this quartet, in 1917).

Sherman joined Borromeo violinist Nicholas Kitchen and cellist Yeesun Kim in a loving and exciting Brahms B-major Trio that moved from heart-easing consolation through mysterious stealth and galloping energy to that final rapturous waltz (Brahms anticipating his Liebeslieder Walzer), as if the dancers kept waltzing themselves into some private alcove where they could pour out their most passionate declarations.

Each moment flowed so effortlessly into the next — even from piece to piece — that you’d think this is easy to achieve. The uninhibited Brahms, after intermission, came as a great release from the muted, gossamer coda of the Bartók. Brahms’s own breathtaking coda created a thrilling resolution not only to the preceding movements but to the entire concert. And Sherman, as rich in support as in bravura, played as if his new partnership with Kitchen and Kim were as longstanding as their own. (There’ll be more Borromeo at Rockport this weekend, June 21 and 23.)