His solo performance of the Second Knee Play from Einstein on the Beach, would have invited comparison with a Bach Partita had he not already played Glass's newer response to that form, written especially for the player and almost 40 years newer. It is beyond debate which is the most important phase of the composer's long career. Of the other recent pieces in Saturday's programme, the pair's duet sequence of music for a production of Jean Genet's The Screens was the most appealing for sounding the least like "Glassworks".