“Music for a while / Shall all your cares beguile,” as English poet John Dryden put it, but who shall beguile the cares of the musicians? Shortly after the Scottish tenor Paul Agnew had sung Henry Purcell’s setting of that text, in a beguiling concert at La Maison Francaise on Monday night, the harpsichordist accompanying him, Beatrice Martin, felt faint and asked her colleagues to pause the concert in the middle of a dance from Purcell’s G Minor Suite.

Martin and her colleagues, viola da gamba player Anne-Marie Lasla and theorbist Thomas Dunford, recently arrived in the United States with Les Arts Florissants, to perform what is by all accounts a magnificent revival of Lully’s “Atys” at the Brooklyn Academy of Music. Up to that point, no audible sign of fatigue was evident in Martin, and after the group took an impromptu intermission and reorganized the second half, she played with the same precision and passion as in her magnificent performance at the French Embassy last year.

Agnew’s voice has lost some of its former power — he has a minor part in “Atys,” rather than one of the lead haute-contre roles that helped make him famous in recordings under William Christie — but it retains most of its beauty and all of its considerable expressivity, especially in this kind of intimate music. Known primarily as a French baroque specialist, Agnew relished the diction of Purcell’s English texts with obvious delight. The continuo players followed his agile flights of running notes and mercurial shifts of tempo with admirable fluidity.

Dunford gave a melancholy and subtly crafted rendition of John Dowland’s famous “Lachrymae” on his theorbo, a large lute, as well as spontaneously offering Johannes Kapsberger’s Sixth Toccata to cover Martin’s absence. An encore by all four musicians featured one of the most beautiful pieces from Purcell’s sacred music, the evening hymn “Now that the sun hath veiled his light.”

Downey is a freelance writer.