Der Stein der Weisen Tamino and Sarastro). "Der Stein der Weisen" may have provided a model for that work, as the two have a similar structure and source. The work was initially popular, but was largely absent from the standard repertoire for the two centuries after 1814, American musicologist David Buch announced the discovery of a Viennese score with attributions to all five composers. This was taken by some to indicate that "Der Stein der Weisen" was a previously unknown Mozart work, although in fact only a duet ("Nun liebes Weibchen", known as the "cat duet") and two sections of the act 2 finale
Piano concertos by Wolfgang Amadeus Mozart it was probably J.C. Bach, whom Mozart admired, who introduced the structural innovation of allowing the keyboard to introduce new thematic material in its first entry. Concertos Nos 1–4 (K. 37, 39, 40 and 41) are orchestral and keyboard arrangements of sonata movements by other composers. The next three concertos (K. 107/1, 2 and 3), which are not numbered, are arrangements of piano sonatas by J.C. Bach (Op 5. Nos. 2, 3, and 4, all composed by 1766). Based on handwriting analysis of the autographs they are believed to date from 1771–72. Concerto No. 5, K. 175 from 1773 was