At their sublime best, Le Poème Harmonique’s recordings are so singular that comparisons with other performances of the same repertoire aren’t relevant, so much has this early music group evolved into something that follows its own expressive rules that may be solidly based in current musicology precepts but never feels restricted by them. Les Arts Florissants have more exterior sheen; Les Demoiselles de Saint-Cyr, in the Clérambault Miserere, an attractive soft-focus quality in a 1993 Virgin recording that predates the one-voice-to-a-part performance practice that has swept through the early music world. Le Poème Harmonique offer their trademark blend in which each of the three voices here sound like extensions of each other, yielding clarity that’s particularly revealing in the dissonant tension in Clérambault’s more intense tone-painting while also projecting a gravity that past generations generated with larger vocal contingents.

The piece can lose credibility in moments of seemingly forced levity that now come off like a bald attempt to ingratiate. But the distinctive acoustic of the Chapelle Royale at Versailles (where this was recorded) is an atmospheric factor reminding listeners not to impose modern notions of solemnity upon this 18th-century music. In any case, the intense humanity of the singing becomes a unifying factor in the piece.

Though I’ve rarely heard a recording of Couperin’s Leçons de Ténèbres that I didn’t want to hear again – so much does it inspire the best efforts of its performers – this one stands with the best (including Emma Kirkby’s, made years apart, first on L’Oiseau-Lyre and then on BIS), the strengths being the purity and accuracy of the vocal lines and a sense of how forward-looking the music must have sounded in its own time. The body of each Leçon establishes a certain harmonic playing field familiar to anyone who knows the French Baroque, though this recording underscores the composer’s rhapsodic departure from all of that when announcing each verse with the Hebrew letters, with music that can waft towards the Holy Land with hints of Middle Eastern influence.