The Magic Flute also acknowledge an influence of Freemasonry. For detailed discussion of sources see , as well as "Libretto of The Magic Flute". In composing the opera, Mozart evidently kept in mind the skills of the singers intended for the premiere, which included both virtuoso and ordinary comic actors asked to sing for the occasion. Thus, the vocal lines for Papageno—sung by Schikaneder himself—and Monostatos (Johann Joseph Nouseul) are often stated first in the strings so the singer can find his pitch, and are frequently doubled by instruments. In contrast, Mozart's sister-in-law Josepha Hofer, who premiered the role of the Queen of
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