Capriccio, Strauss's last completed opera and the work he considered his "testament," hasn't been heard at Covent Garden since 1991. Its current revival in concert is to some extent a vehicle for Renée Fleming, long associated with the central role of the Countess Madeleine, emotionally torn between the poet Olivier and the composer Flamand, who, we gradually realise, are also the fictional co-authors of the piece we are watching.

Fleming has been in better voice than she was on opening night: there were a couple of moments of imperfect control in her soft, high singing, and an occasional hardening of tone under pressure. The subtlety of her characterisation, however, remains remarkable. Emotional anguish is balanced by wit and self-mockery. There's something erotic about the exaltation she feels at being a muse to the creative figures in her life. Strauss never tells us which of her prospective lovers she will choose, but Fleming exits with a knowing smile that hints at multiple configurations, while keeping the mystery intact.

Capriccio, however, should never be a one-woman show. The great Bo Skovhus, too long absent from Covent Garden, is marvellous as the libidinous, if prosaic Count (the heroine's brother), hankering after an affair with Tanja Ariane Baumgartner's self-assured Clairon. Christian Gerhaher's impetuous, slightly prissy Olivier makes a perfect foil for Andrew Staples's ecstatic Flamand. Peter Rose sounds good as La Roche, but hasn't quite got the requisite anger and authority for his big monologue, widely regarded as constituting Strauss's own demands for artistic continuity and humanity in the face of nazism (the work was first performed in 1942). Andrew Davis's conducting is passionate, lyrical and admirably free from self-indulgence.

• Did you catch this gig – or any other recently? Tell us about it using #GdnGig