Bernard Roberts 70th Birthday Recital, St John's, Smith Square, London

Bernard Roberts never shot to fame by winning a competition, nor covered himself in glory by standing in at short notice for an indisposed star, but he has certainly proved his staying power. I first came across him as a student when he was one of the youngest teachers at the Royal College of Music. It was many years before I heard him play, when after a tremendous performance of Beethoven's Eroica Variations at the Queen Elizabeth Hall, the critic Peter Stadlen said to me: "Why haven't I heard of this man before?" Since then Roberts hasrecording all Beethoven's Piano Sonatas direct to disc.

It's in the Austro-German classics from Bach to Brahms that he has earned a reputation as a player of unusual honesty and power, and his 70th birthday recital last Friday drew from them exclusively.

The programme was not quite as predictable as that implies, for to start, Roberts chose a little-known Sonata in E major (No 31) by Haydn, written before the composer's more popular piano music. Far from making a dainty miniature of a piece that would originally have been played either on a harpsichord or on a small-toned early piano, Roberts projected it on a Steinway as generously as he would a piece from the 19th century. Never has piano tone filled St John's more surely, and the three-part texture of Haydn's second movement Allegretto sang out particularly boldly, yet without seeming forced.

Roberts chose to follow Haydn's pithy piece with Schubert's by-no-means pithy Sonata in D major, D850. It was a joyous relief when the first movement burst into life at a lively tempo that promised - and sustained - impetus without pomposity. As in Haydn, Roberts up-graded quiet passages so that they reached our ears clearly.

His way with Schubert's second movement was surprising, because he didn't mould it with the soothing "legato" most pianists apply here, but instead, made it firm and crisp, and observed Schubert's articulation marks punctiliously. Throughout its leisurely elaborations he maintained that basic firmness.

The finale doesn't confine itself to the innocent insouciance of its main theme, and one of the dramatically pugnacious episodes exposed a particular feature of Roberts's playing: a way of having his hand in position so that there was a slight hesitation after a jump to make sure of a safe landing.

This was to crop up again in the big work following the interval - Brahms's Variations and Fugue on a Theme by Handel - and it made for slightly heavy going in the final variation, before the authentic sense of struggle in the fugue.

Roberts is not a colouristic pianist, and few would call Brahms that kind of composer, but sometimes I wanted sharper characterisation. You felt, at the end, rather as if you had eaten an extremely substantial, high-protein meal, and slightly ungrateful for missing something piquant by way of added savour.