It is surprising that the mighty Diabelli Variations has had so few recordings on a period piano since Arkiv’s pioneering set by Jörg Demus in 1978 (now available on Eloquence; an interesting set that included 32 of the 50 other variations of Diabelli’s anthology). Andreas Staier raised the bar with his 2012 recording on Harmonia Mundi: a revelatory reading, taking every opportunity to exploit the varied colours of his instrument, but his liberal use of the moderator and Janissary pedals might be too much for some listeners.

Collectors of Ronald Brautigam’s superb complete survey of Beethoven’s keyboard output have been eagerly awaiting his account for its concluding volume and I doubt they will be disappointed. He uses yet another superb Paul McNulty instrument; this time a copy of an 1822 Conrad Graf that approximates that which Graf presented to Beethoven in 1826 – with four strings per note. Its lovely limpid treble points forward to later pianos but retains the fortepiano’s nut-brown colour in mid and bass registers – and it sounds glorious thanks to the state of the art recording.

Brautigam allows the beauty of the instrument to shine, using its particular tonal characteristics to illuminate...