Never one to rest on her laurels, Renée Fleming has always been willing to expand her repertoire into new territory. Her latest recital was a foray into musical jugendstil as embodied in works by composers active in Vienna at the turn of the 20th century – a natural progression from her long association with music by Richard Strauss, whose Zueignung she offered as one of several encores.

Prefacing Mahler's Rückert Lieder with a group of Hugo Wolf's Goethe settings, the first half had its cautious moments. Fleming wasn't always helped by her pianist, Maciej Pikulski, whose playing suggested impressionistic vagueness in music that should sound more purposeful and sinewy. But when Fleming finally let rip at the climax of Mahler's Um Mitternacht, the mix of sensuality and spirituality proved intoxicating. And Ich Bin der Welt Abhanden Gekommen has rarely sounded so exquisite.

The second half was altogether more secure. The high point was Zemlinsky's Five Songs to Texts by Richard Dehmel, a brooding meditation on the crisis in his sister's marriage to Schoenberg, which found Fleming at her most intense as well as at her most beautiful.

Pikulski, meanwhile, finally struck form in a pair of early Schoenberg songs, Erwartung – not to be confused with the opera of the same name – and Jane Grey, a study in morbidity that sounds like a sketch for Gurrelieder. Fleming was wonderfully declamatory with it.

She closed with Korngold, ending with an aria from his Strauss-based operetta Walzer aus Wien, written as the threat of nazism loomed, and turning to him again for the last of her encores, Mariettas Lied from Die tote Stadt. Here her voice rose rapturously into the stratosphere, and Pikulski did ravishing things with the closing postlude.

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