Handel’s “Acis and Galatea,” like his later “Semele,” is rightly considered an opera, even if it went by other labels during the birth of English opera. Both works have rightly been accorded recent productions at the New York City Opera, “Semele” just last fall. But “Acis and Galatea,” it seems, was originally given by quite modest forces, in a performance with soloists doubling as choristers and perhaps as few as seven or eight instrumentalists.

The Aulos Ensemble, an esteemed period-instrument group in business since the early 1970s, reverted to that kind of approach for a performance Tuesday evening in the Medieval Sculpture Hall of the Metropolitan Museum of Art. Its performance proved to be most adequate to convey the work’s considerable pastoral charm.

The story involves the simplest of love triangles. Galatea, a part-divine sea nymph, is in love with the shepherd Acis, but Galatea is also craved by the giant Polyphemus, who in a torment of jealousy crushes Acis beneath a rock (or “mossy ruin”). The text by John Gay and others has its elements of humor, but they do not detract from the genuine grief triggered by Acis’s demise.

The infectious opening chorus, with its instrumental drone, immediately establishes a rustic ambiance, and much of what follows consists of da capo akin to those of Handel’s Italian operas. The performance here was, unfortunately, on an even smaller scale than was necessary, since the da capo repeat of the opening chorus and of three arias was suppressed; also omitted was the role of the shepherd Damon and his aria.

Still the singers had much to do. The soprano Kendra Colton sang Galatea with admirable clarity and directness. Her feigned irritation with the instrumentalists when they didn’t stop playing when she sang “Hush!” in an aria was a little precious. But she was effective in a recitative in which Galatea exerts her divine powers to convert the dead Acis into an immortal fountain. Ms. Colton allowed a climactic high note to reverberate until it died away before she went on.

The veteran early music tenor John Elwes, in robust, focused voice, was a fine Acis, apart from some pinched high notes in the martial aria “Love sounds th’alarm.” He and Ms. Colton made a delightful impression in their almost giddy duet, “Happy we!” William Hite’s sweeter, more subdued tenor contrasted nicely in the shepherd Damon’s music. Bass Curtis Streetman was an aptly lumbering presence as Polyphemus and produced a sound that underscored the giant’s might. Krista River, an alto, joined the other singers in the choruses.

The five instrumentalists of the Aulos Ensemble, augmented by three more players, supported the singers handsomely. At times the presence of a conductor might have enforced great dynamic contrasts or better shaped instrumental ritornellos, such as those of Damon’s beguiling “Consider, fond shepherd,” so evocative of nature. But there were many fine individual contributions, not least that of oboist Marc Schachman in Galatea’s touching solo with chorus “Must I my Acis still bemoan.”