One of Haydn’s few pre-London sonatas to have entered the popular repertoire is the D major, No 37, from the set of six published by the Viennese firm of Artaria in 1780. The sonatas were dedicated to the talented sisters Franziska and Maria Katherina von Auenbrugger, whose playing in aristocratic salons drew the admiration of both Leopold Mozart—never one to dish out compliments lightly—and Haydn himself.