An infrequent New York appearance by the admired mezzo soprano Jennifer Larmore was surely the main draw for many in the audience at Zankel Hall last Thursday evening. So the presence of Ensemble Matheus, a dynamic, up-and-coming French period-instrument band making its American debut under its director, the violinist Jean-Christophe Spinosi, probably came as an unexpected bonus. If the evening had a mild bait-and-switch element, it likely left few complaining.

For fans of Ms. Larmore, there were seven arias, mostly of a brilliant and virtuosic nature. “The most recorded mezzo of all time,” as her Web site proclaims, Ms. Larmore has explored broad stretches of early 19th-century operatic terrain for the Opera Rara label, so it came as a bit of a surprise to find her hewing to the tried and true in her Baroque selections here.

It was not all that long ago that any aria from Handel’s “Giulio Cesare” would have been a rarity, but the surge in popularity of Baroque opera has changed that. Ms. Larmore nicely evoked the opening of that opera with Caesar’s initial arias, both florid, the triumphant “Presti omai” and the scornful “Empio, dirò, tu sei,” bringing to the latter an aptly venomous articulation. She went on to demonstrate the variety of emotions that elaborate coloratura can evoke in Handel with her spirited renditions of the joyful “Dopo notte” (“Ariodante”) and the tempestuous “Venti, turbine, prestate” (“Rinaldo”), another blockbuster. A rage aria from Vivaldi’s “Orlando furioso” emerged as similarly incisive.

Another of Caesar’s arias, “Aure, deh, per pieta,” sung expressively and with fine legato line, showed a more contemplative side, as did the perennial favorite, “J’ai perdu mon Euridice” from Gluck’s “Orphée et Eurydice.” The latter is sometimes said to be too sunny musically for an expression of grief, but Ms. Larmore’s sense of urgency made it here a plausible lament. With the passage of years, however, Ms. Larmore’s tone has lost some of its luster. The sound is drier than it once was, nor did her singing dominate the small hall to the extent one might have expected. Still, I would prefer her in a heroic Handel role over most countertenors.

As for the accompaniments by Ensemble Matheus, they got better and better. The flimsy sound the strings brought to the detached chords of “Presti omai” and their wispy tone in the accompaniment figure preceding “Aure, deh, per pieta” were disappointing at first. But Mr. Spinosi is nothing if not a spontaneous conductor, and the telling details he brought to “Dopo notte” contributed handily to its ecstatic mood. In “Venti, turbidi” he took up the violin and, joined by bassoonist Antoine Pecqueur, helped make that aria sizzle with their expert deliveries of the obbligato lines. Two engaging concertos were also on the program. Telemann’s Concerto for Flute and Recorder in E minor, with Jean-Marc Goujon and Luis Beduschi as the able soloists, paired two instruments of similar but slightly different timbre, the piping purity of the recorder and the more complex, veiled sound of the flute. Yet in the many passages in which the soloists played together, the blend was lovely, the differences indiscernible. The concerto is distinguished by Telemann’s allusions to Polish and Moravian folk music in the earthy last movement, which all played with lusty foot-stomping vigor.

Mr. Spinosi, joined by concertmaster Laurence Paugam, was also heard in an exuberant account of Vivaldi’s Concerto in D Major for Two Violins and Orchestra, RV 513, a piece characterized by greater motivic invention than Vivaldi is often given credit for. Both soloists played with utter confidence and with tone that was shining yet had an apt period mellowness.