Keith Humble's third piano sonata was written in memoriam for Humble’s friend Bill Hopkins, an outstanding British composer and student of Barraqué who died in his thirties. It was premiered by Humble at an Astra concert in 1985.

The work is in three parts (Statement – Commentary – Epilogue), the two brief outer movements framing the central Commentary which, rather than being developmental, unfolds as a series of varied expressive and gestural glosses on the opening material. This musical continuity has some parallels with the late sonatas of Debussy.