TO call Alfred Brendel a pianist's pianist would be perhaps no more enlightening than to call him a thinker's thinker, a poet's poet, or a Schubertian's Schubertian. Besides, it might not even be true, because not all pianists like each other. But he is surely a musician's musician, capable of threading his way from Schubert to Mozart to Haydn and back to Schubert without interrupting his train of thought, or making the little witticism with which he ended Haydn's short two-movement sonata in D major sound any less delightful than the grace with which he brought Schubert's big G major sonata to its close.

Charm, admittedly, is not something for which you specially turn to Brendel. He is too serious and too quizzical for that, but when he allows it in, as in the middle of the G major sonata's scherzo - or, for that matter, in the middle of the B major's at the start of the programme - it makes its point without cloying. The tempo may be eased, the touch may soften, but always within the character of the performance.

That, among many other things, was what made last night's recital in a packed Usher Hall so rewarding. Brendel knew exactly how much tone to produce on any note, how to articulate the scales in the first movement of the Haydn in such a way that there were no long scales, how to make the singing beauty of the slow movement of Schubert's B major sonata a question of shape and structure as well as of song.

Only in Mozart's B flat sonata, K570, did he approach the music differently. Whereas Haydn and Schubert, under Brendel's fingers, emerged in various ways linked, Mozart was more lightly shaded - not necessarily less expressively but so as to suggest that the music did not need to wear its secrets on its sleeve.