Florian Boesch is never a singer to take for granted. In Schwanengesang he changes the (posthumously) published order of both the Rellstab and Heine groups so that each charts a gradually darkening landscape. There is no place for the charming, wistful ‘Die Taubenpost’. But then charm is not Boesch’s way. In songs that call for a smile in the tone he sounds nonchalant, almost detached, bending rhythms, shortening sustained notes and sometimes resorting to a conversational parlando. I hear neither roguishness nor amorous yearning in ‘Das Fischermädchen’. In ‘Ständchen’ he makes the most casual, laid-back of seducers.

The songs of loss and alienation that predominate are a different matter. I would still have preferred a truer legato in ‘Ihr Bild’ and ‘Am Meer’. But abetted by Malcolm Martineau’s imaginative, clean-textured playing, Boesch unfurls his full expressive and dynamic range to compelling effect. At a mobile tempo, ‘In der Ferne’ has a grand, arching sweep, building surely to a searing climax, while ‘Kriegers Ahnung’ encompasses sombre foreboding, tenderness and, finally, numb desolation. Boesch is in his element railing against an intolerable burden of suffering in ‘Der Atlas’ (the dotted bass ostinato etched in granite by Martineau). And few recorded performances of ‘Die Stadt’ and ‘Der Doppelgänger’ since Fischer-Dieskau can match Boesch’s haunted intensity, the latter climaxing in a lacerating, horrified ‘meine eigene Gestalt’.

The Goethe settings are also well suited to Boesch’s temperament and colouristic range. For the doleful meditations of the blind old Harper he finds a blanched, abstracted tone. He sneers and taunts without melodrama in ‘Prometheus’, Goethe’s bitter denunciation of theocratic tyranny, and distils a mingled humility and gravitas in its philosophical antithesis, ‘Grenzen der Menschheit’, enhanced by the firm resonance of his low notes. Boesch’s almost expressionist style is certainly controversial in Schubert. But at his best he and Martineau can convince you that, for the moment, theirs is the only way.