Franz Schubert seems to have been particularly attracted to a-minor. Not just one but three of his piano sonatas are in this key. The earliest of them, D 537, was composed in March 1817 and was simultaneously his first completed piano sonata ever. It is characterised by concise brevity. The three-movement form dispenses with the usual scherzo. It is far removed from the drama of its a-minor sibling works; meandering modulations often lead to distant harmonic regions and lighten the mood to major...