Pianist Llyr Williams is tackling the Beethoven sonata cycle over one year in a series of concerts at Perth Concert Hall, but other venues are reaping the occasional benefit, too. The Llandeilo festival was one of the first places to hail Williams's genius and, back on familiar territory, he was in relaxed form for a recital of middle-period Beethoven.

He brought out the playfulness of the first and third sonatas of Op 31, as well as the more cerebral working-out of ideas. In these sonatas, Beethoven is still audibly Haydn's pupil, and Williams's clarity of articulation meant that in the G major sonata, Op 31 No 1, the rhythmic quirks had a witty sparkle, balanced by a lyrical shaping of the melodic lines, while the final Presto of Op 31 No 3 had a fiery drive.

Combining acute sensitivity with intellectual rigour, Williams's insight into harmonic language – its emotional and structural significance – marked the Sonata in D minor Op 31, No 2. The veiled mystery of the opening arpeggiated chords was wonderfully poised; and his understanding of the composer's revolutionary use of the sustaining pedal was revealed brilliantly in the finale of the Waldstein sonata, Op 54. This piece represents a milestone for Beethoven, and the stature of Williams's performance suggested that he is approaching a similarly important transition.

As if to reinforce that, his encore was no mere bagatelle, but the third movement of Charles Ives's Concord Sonata, "The Alcotts". Delivered with unerring perception, it was a perfect ending to a remarkable evening.