When Günter Henle founded his Urtext publishing house in 1948, he opened his catalogue with our two-volume edition of Mozart’s complete piano sonatas, these still bear the publisher’s numbers HN 1 and HN 2. The four-digit order numbers HN 9001 and 9002 merely designate the reduced-sized pocket scores of these larger reference editions, and are textually exactly the same.

Naturally, both Mozart volumes (large and small) have been revised many times over the years, enabling G. Henle Verlag, un...