It has become fashionable of late to describe Mozart's piano concertos as "operatic". The epithet is perhaps justified. Alfred Brendel's performance of Nos 17 and 25, with the Scottish Chamber Orchestra under Charles Mackerras, certainly brought out the almost vocal lyricism of Mozart's piano-writing, the dramatic ambiguity of the relationship between soloist and orchestra, and the stylistic kinship of the concertos to the stage works that followed. No 17, mixing metaphysics with humour, pre-empts The Magic Flute. No 25, in which the soloist's meditations are contrasted with the orchestra's stately ceremonials, explores the conflict between private emotion and public ritual that informs La Clemenza di Tito.

As might be expected, Brendel and Mackerras proved well-nigh unbeatable in Mozart. They are both performers who combine a far-reaching intelligence with emotional subtlety, and the end results were immaculate. Concerto No 17 is seemingly piano-driven. The work's high point is its slow movement, with its irresolute melodies hovering between recitative and aria. The quiet sincerity of Brendel's playing here, limpid yet urgent, coloured the orchestral response as the phrases gained weight and emotional meaning with each repetition. In No 25, Brendel adopted a slightly more incisive tone; the piano's ruminations consistently broke through the orchestra's architectural grandeur, gradually undermining its force. I can't imagine either work done better.

Less convincing was Mackerras's decision to preface the concertos with Schubert's Sixth Symphony: one of Mozart's orchestral works might have been more appropriate. Schubert was a flawed symphonist and the Sixth, more than most, exposes the weaknesses in his methodology, namely his dependence on cumulative melodic repetition rather than thematic development. The Sixth also acknowledges its influences - Mozart in the first movement, Beethoven in the scherzo and Rossini in the finale - rather too obviously. The playing was flawless, with beautifully honed woodwind and strings, and Mackerras conducted it with tremendous panache, but he couldn't disguise its faults or prevent the occasional longueur.