John will explore pieces written over ground basses: repeated melodic patterns in the bass line over which the composer builds ever-changing harmonies and textures. Music will include some by that master of the ground bass, Henry Purcell (the Chaconne from King Arthur); two pieces by Pachelbel including his ubiquitous and very clever Canon; works by Buxtehude; and the Introduction and Passacaglia from the Sonata no. 8 in E minor by Rheinberger.