MUSIC / Spread too thin: Isabelle Vernet - Wigmore Hall, London

Again, a Wigmore Hall singer that everyone wanted to hear. The soprano Isabelle Vernet made a big impression singing Nuits d'ete by Berlioz at last year's Proms, and was a Cardiff Singer of the World finalist the year before. The audience for her all-French programme arrived on Monday night expecting to enjoy itself: and did, slightly more than the occasion warranted.

Isabelle Vernet's choice of songs was alluring: Faure, Poulenc, Reynaldo Hahn, Duparc, Satie and Ravel, with two comic songs by Manuel Rosenthal to finish, and a couple of encores moving further into the world of cabaret. The casual, roguish ending succeeded. Vernet showed that she could flirt, confide and play the goggle-eyed innocent with the best; and the well-nourished charm of her voice was spontaneously effective.

The rest of her work on Monday lacked concentration. One reason might have been that there were too many composers, with not enough opportunity for artist or audience to find out what any of them was really saying. The long reflective vocal spans characteristic of Faure, or Hahn, or Duparc, with their rippling pianistic subtexts, did not come naturally to her. Nor did the mostly mezzo range that she had chosen seem to be her best vocal area. Although her voice was rich enough, it came into focus far more compellingly in the rare high passages where there was a long enough run of notes for her to open up.

It was difficult to disentangle interpretative shortcomings from technical unease. She sounded as if she were trying to scale a big sound down, and losing road-holding ability in the process. The sharply turning pitches of Duparc's Chanson triste had her skidding almost out of control. It seemed, too, as if in trying to come down to an intimate form of delivery she had absolved herself from the necessity of attacking the notes cleanly: there were many scoops. More surprisingly still, there were shortages of breath.

Faure's Au bord de l'eau made quite an exciting start to the evening. Vernet enjoyed its chromatic sinuosities, and gave us glimpses of that fresh, huge sound at the top whose subsequent appearances were so rare and so intriguing. But already there were places where the tone didn't arrive, just the breath: the last note, for instance.

The best moments were always with the lighter moods and the faster songs. Poulenc's Les gars qui vont a la fete was thrown off deftly; Hahn's Reverie, with its gentle Latin-American gait, was informal and touching. The faux-naf infant dialogue in Satie's Dapheneo was placed with an exactitude and humour that won hearts, while the combination of vocal warmth and fine Spanish piano filigree proved irresistible in Ravel's La flute enchantee. Neil Beardmore, accompanying, was supple, discreet and supportive: a bit bland sometimes. He could have incised the piano line more confidently where it lay above the voice (as in Duparc's Elegie), or where there were introductory solos. Bolder, more unusual readings might have offset Vernet's lack of emotional energy in delivering the more intense texts.

If there is a moral to this story, it is probably just that recital singing requires a particular kind of preparation which becomes more difficult when a singer is mostly working on big stages. Vernet's bejewelled voice is stunning at its best. But on Monday it needed to be wielded more efficiently and exactly, with more literary insight.