Emanuel Schikaneder elements and traditional fairy-tale themes (see "Libretto of The Magic Flute"). Schikaneder took the role of Papageno—a character reflecting the Hanswurst tradition, and thus suited to his skills—at the premiere. According to the dramatist Ignaz Franz Castelli, Schikaneder also may have given advice to Mozart concerning the musical setting of his libretto: The late bass singer Sebastian Mayer told me that Mozart had originally written the duet where Papageno and Papagena first see each other quite differently from the way in which we now hear it. Both originally cried out "Papageno!", "Papagena!" a few times in amazement. But when Schikaneder
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