"Magic's what I try to give to people," Renée Fleming sang. The words come from A Streetcar Named Desire, which André Previn turned into an opera for Fleming several years ago.

The partial standing ovation that followed her performance of the aria (one of her encores in her recital with pianist Jean-Yves Thibaudet) proved that the magic is still potent in certain quarters.

Fleming is cultish, trailing in her wake the reputation of having the most beautiful soprano voice in the world. The sound she makes - voluptuous in its easy liquidity - is unquestionably astonishing, although her singing always has you wondering whether beauty in itself is ever quite enough in performance.

Fleming's recital formed part of the world tour of her latest album, Night Songs, a sequence of erotic nocturnes by composers from around the turn of the 20th century. Her programme is consequently characterised by a certain emotional sameness that avoids dramatic juxtapositions or conflicts within groups of songs.

On the platform, she exudes an air of cultivated glamour, sweeping on at the beginning in a gown that suggests an 18th-century grande dame in provocative boudoir disarray, returning after the interval looking like an enigmatic art nouveau siren.

Her voice rolls through the surging chromaticism of Rachmaninov's songs, sustaining their rapturous lines with a combination of abandon and delicate poise, though we're only intermittently aware of the fact that she's singing in Russian.

In Debussy's Chansons de Bilitis, we get more of the text, though the opulence of Fleming's voice suggests erotic knowledge, when what Debussy was after was a questioning pubescent innocence.

She's gorgeous in Strauss, and also opts for songs by the little-known Austrian Joseph Marx, drawing parallels between herself and vocal eroticists such as Ljuba Welitsch and Leontyne Price. Selige Nacht is exquisite and Pierrot Dandy reveals shafts of irony and wit absent from the rest of the recital.