Louise Winter (mezzo soprano), Julius Drake (piano)

First impressions of mezzo soprano Louise Winter at Saturday morning's opening Coffee Concert of the Belfast Festival were of a singer with a delivery which inclined towards the Wagnerian. Hers is a style which thrives on the production of impressively projected tone. But the way she slides into notes tends to airbrush out the precise nature of the rhythmic values, and her usually heavy vibrato can make the pitch of notes seem vertiginously vague. It's a manner of singing which can be genuinely thrilling when riding a climax over the swelling opulence of Wagner's orchestra. With only a piano for support, even in Wagner, it tends to be problematic.

Winter's approach, then, could hardly be expected to score much success in the songs of Brahms, long regarded as the polar opposite of Wagner in the ideological musical wars of the later 19th century. And, unexpectedly, the diluted post-Straussian songs of Korngold - she sang the five songs of his Op. 38 - didn't respond too well, either, the thickened sounds of the last two settings in English giving a clear indication of the intrusive baggage that can come with such a burdened delivery.

The remaining works provided surprises, too. Wagner's Wesendonk Lieder - acted out, like everything in the programme, rather than merely sung - never quite gelled. But when Winter toned down her delivery for Haydn's cantata, Arianna a Naxos, it was as if a new source of illumination had been found, revealing contours, shades and inflections that had elsewhere been frustratingly blended together.

Julius Drake was an ever-attentive if musically fussy partner at the piano.