Hummel’s arrangement of the Piano Concerto in D minor, K466, the first of the series to appear, dates from 1827. This concerto was certainly the most popular of all Mozart’s piano concertos, both during his lifetime and after. Other composers besides Hummel arranged the work, among them Johann Baptist Cramer, Friedrich Kalkbrenner and Heinrich Anton Hoffmann, and their versions provide further possible solutions to the “incompleteness” of Mozart’s text.