Opera came to Venice wearing a mask. Troupes of itinerant entertainers had long been a feature of Carnivale, as had the early forms of musical storytelling they brought to the public theatres of La Serenissima. By the mid-1600s, permanent resident companies were being formed with the sole purpose of staging ever more extravagant choral dramas during the pre-Lent season. Unlike early opera in Florence and Mantua where it had originated, the Venetian equivalent was as enthusiastically commercial as it was populist. No composer understood the phenomenon better than Francesco Cavalli. In January 1649, his shamelessly provocative recasting of the Greek myth, Giasone, premiered at the Teatro San Cassiano. Seventeenth century Venetian tourists in the audience gasped. Even by the notoriously liberal standards of the indulgent Adriatic republic, Cavalli’s celebration of sensuality underscored by perversity was a shocker. A spectacular crowd-pleaser, bawdy, anguished and uproarious, the piece flourished in active performance until the early 1700s.

The Toronto Consort’s engaging concert offering of the now infrequently presented early Baroque hit can only hint at Giasone’s outrageous theatricality. Its lush musical values, however, are showcased with sparkling clarity. Guided by the fluid conducting of artistic director David Fallis, singers and period orchestra serve up lyricism, laughter and love.

A blend of Euripides’ Medea and an antiquated epic, the Argonautica by the all but forgotten poet Apollonius, the Giasone story forms an altogether irreverent tale. Like its composer, librettist Giacinto Andrea Cicognito knew all the right notes to sound.

Apollo and Cupid hotly debate the tale about to unfold. Jason, the brash seafarer, Apollo insists, is destined for glory as husband to Medea, illustrious demi-goddess. Cupid thinks otherwise. Fate may forecast fame, but a union of hearts is always uncertain.

Far from family and home on the isle of Colchis, Jason awakens to a stern rebuke from Bessus, a fellow Argonaut. The Greek leader’s torrid affair with an unidentified maiden has robbed him of his desire to seize the Golden Fleece. Jason yawns. Mighty deeds can wait. Love-making will guide his fortunes. Medea, ruler of Colchis, has her own agenda, too. Casting aside her former lover, Aegeus, she confronts Jason, dressed for the first time as a queen, with news that the mystery woman he has been courting is she. Jason is astonished. He and Medea rejoice in their mutual passion.

Meanwhile, Hypsipyle, Jason’s wife, desolate and rejected, arrives at a nearby outpost to seek her long lost husband. Orestes, her spy, has learned of Jason’s unfaithfulness thanks to an encounter with Demo, the island’s resident fool. Informed of her husband’s intention to capture the elusive Golden Fleece, Hypsipyle waits patiently, hoping for a chance rendezvous.

Medea, sparked by her unquenchable lust for Jason, summons the fiends of hell, pleading for a talisman to protect him from the monsters that stand watch over the fabled artefact. The spirits oblige, presenting her with a magic ring. Jason, shielded from harm, is victorious in battle with the guardian demons. Golden Fleece in hand, he makes his way back to safety.

En route to new adventures, Jason and Medea are intercepted by Hypsipyle who stormily demands an explanation for abandoning her. Remorseful and ashamed, Jason vows to return to their marriage bed. The treasure that lured him away beckons no longer. Medea feigns delight, encouraging husband and wife to reunite with her blessings. Her true feelings are revealed in a whisper. Hypsipyle must die. Jason balks. Hero though he may be, he cannot raise his hand against the woman he once adored. He will enlist Bessus to do the deed. His loyal shipmate will cast Hypsipyle into the raging sea. A mix-up ensues. Bessus misinterprets Jason’s instructions. Medea is drowned by mistake. Or is she? Aegeus rescues his cherished Queen. Medea’s love for him is rekindled and new hatred ignited. It is Jason, the betrayer, who deserves death now. Aegeus lunges with his dagger. Hypsipyle snatches it from his grip. Deeply moved by her plea for reconciliation, a repentant Jason takes Hypsipyle into his arms.

All characters re-appear. Lovers are rejoined. The air is filled with song.

From bickering gods to monsters to a chorus of happy endings, Cavalli’s opera is utterly over the top. The low brow and the low-born collide with the lofty ideals of nobles, commedia dell’arte meets the classics, the grotesque vs. the divine. Sex flows as freely as arias. Virtuous role models are in short supply. Jason is treacherous. Medea is cold-blooded. Their friends and servants mock them. This is an opera of knotty paradoxes where the only constant is the sensuous ebb and flow of its exquisitely seductive score.

By far the best known living composer of public opera in mid-seventeenth century Venice, Cavalli, unlike Monteverdi whose mantel he inherited, wrote for a modest-sized orchestra. The Toronto Consort’s 11-player ensemble — violins, recorders, harpsichord, baroque guitar, theorbo, viola da gamba and harp — provides an active, flexible platform for launching Giasone’s instrumental pyrotechnics. Playing is nothing short of masterful throughout the full range of orchestral challenges. Giasone’s innumerable recitatives, refined by Cavalli into expressive, stand-alone elements for continuo and voice, are hushed and handsome. Arias are accompanied with breezy assuredness. Interludes are zestful and stirring. The little dance preceding Act II written, as the program notes indicate, not by Cavalli but by his contemporary, Gasparo Zanetti, is particularly fine.

In the trouser role of Jason, mezzo Laura Pudwell and soprano Michele DeBoer as sorceress queen Medea strike powerful opposing yet complimentary singer actor poses, Pudwell with her near contralto-like timbre, DeBoer with her more soaring, crystalline tone. If Jason is heart, Medea is head. The psychology at work here is palpable and Cavalli frequently exploits it, connecting his two principals with long chains of joint recitative. Pudwell and DeBoer link voices with great strength and emotion. Given a duet, the pair strike vocal sparks. Their intense, fleeting celebration of passion, Ardi pur, o mio ben (“Burn, oh my love”) is ablaze with sentiment. Giasone’s single most spine-tingling moment, Medea’s infernal incantation underlaid with chilling psychotic-like arpeggios played by the orchestra’s vibrant strings, amply demonstrates DeBoer’s ability to command the stage.

Katherine Hill sings Hypsipyle, her bright, centred soprano an ideal match for the purity and innocence of Jason’s long-suffering wife. Hill’s rendition of Cavalli’s sparkling aria, Gioite, gioite (“Rejoice”) Hypsipyle’s Act II shout for joy, is simply charming.

Appearing as Jason’s murderous henchman, Bessus, bass John Pepper portrays a surprisingly affecting thug, life-hardened and world weary. Bass baritone Paul Oros is a grumbly, rumbling Orestes. Tenor Kevin Skelton sings Aegeus, clear-voiced and expressive. Vicki St. Pierre is a cranky Delfa, Medea’s go-between.

In the production’s rowdiest, most rambunctious performance of the night, Bud Roach as Demo, the hunched, stammering fool, turns a Venetian stock character into a figure of pathos, a clown bravely fighting back his tears. Roach’s tenor is expansive. When all but gagged by Demo’s chronic stutter, the dramatic effect is beyond heartbreaking.

Giasone is a rare gem. The Toronto Consort’s spare, gorgeously played, movingly sung concert performance makes it all the more precious.