There are some who still dismiss the phenomenon known as Dietrich Henschel on the grounds that his voice is not classically beautiful, and indeed it could be argued that the basic sound has a metallic quality that won't appeal to those who like their baritones velvet-toned.

Yet truth rather than beauty is what Henschel is about. The reason he is, quite simply, the world's greatest living lieder singer lies in his matchless expressive range and in the emotional intensity that shakes his elegant slender frame and pours from him, overwhelming his audiences and, at times, himself.

Accompanied by Irwin Gage, he sang Schwanengesang, Schubert's final, posthumously published collection. To each song he brings something new, taking you into territory you haven't been before. He transforms Ständchen into a study of obsession, as a rasp of frustration suddenly mars the flow of the lover's serenade.

In Die Stadt, the hollow tone hints at unspeakable emotional degradation. In Der Doppelgänger, he's a madman, whispering his secret ravings in your ear. Elsewhere, we find urbane wit in the posturings of Ade, erotic remorse in the sad humour of Die Taubenpost and genuine rapture in Liebesbotschaft.

When it was over, he was in tears, and the audience was on its feet. One of the greatest things I've ever heard in my life.