In August 2008 John published his fifth book on Beethoven, Treasures of Beethoven, commissioned by Carlton Books/André Deutsch.

This is a unique look into Beethoven’s life. The book contains facsimiles of original documents, such as the Heiligenstadt Testament, the Letter to the Immortal Beloved, as well as other letters, manuscripts and musical sketches. These can be removed from the page, unfolded and studied.

The book also contains several hundred portraits, drawings, landscapes, and pictures of artefacts.

The book is handsomely produced and comes in an elegant slipcase.