There are many profound experiences to be had in a concert hall, but an evening of soprano and mezzo duets isn't one of them. Still, on the disc they brought out last autumn, Barbara Bonney, Angelika Kirchschlager and accompanist Malcolm Martineau managed to pick out some of the more interesting numbers in this frothy repertoire. Many of those made it into this recital - along with lashings of sugary charm, a few girly hugs and a line in the programme from Kirchschlager about how it wasn't only their voices fitting together but their souls, too. Yeuch.

She was right in one way, though: those voices, both expressive and relatively light, are very well matched. It was Bonney who played big sister, apologising for colds that seemed to have emasculated some of Kirchschlager's low notes but left Bonney herself seemingly unaffected.

Mendelssohn's Six Duets seemed a mere warm-up to three from Schumann's Spanisches Liederspiel, which found the pair more animated, responding to the subtle swing Martineau brought to the dance rhythms of Botschaft. Five French songs brought a richer vocal presence from Kirchschlager, and provided some of the evening's least formulaic music. Fauré's Tarantelle was a high-speed obstacle course, with Martineau skilfully maintaining an illusion of gathering momentum. He had fun, too, in the flamboyant interjections amid the singers' flirty entreaties to their imaginary gondoliers in Rossini's Voga, o Tonio. But the most satisfying music came in Dvorak's 13 Moravian Duets: their rustic Czech folk-song idiom is well suited to this combination of voices, while their varying treatment of the texts, whether mischievous or poignant, is closer to the serious lieder tradition.

The only time we got to hear much of either singer on her own was in the long solo passages of the second encore, Gounod's D'un Coeur Qui t'Aime, by which time both were sounding tired. A shame, as a couple of brief forays into the solo repertoire might have given us something to chew on amid all that candyfloss.