Vestas Feuer by Pamina and Papageno in "The Magic Flute"), which has the same key and time signature and was the subject of a set of variations for cello and piano by Beethoven (WoO 46), written 1801. Lockwood also discerns a precedent set by Mozart involving formal structure: an "Introduzione"; i.e. Beethoven's scene forms a separable initial section of an opera having some degree of integrity of both plot and harmonic plan; Lockwood calls the "Introduzione" a "miniplay". Three of Mozart's operas begin with such an "Introduzione": "Don Giovanni", "Così fan tutte", and "The Magic Flute". Beethoven's "Introduzione" has a harmonic structure
Mozart and dance eighteenth-century composers were expected to be adept at producing both 'popular' and 'serious' music, and that there was no categorical difference between the two.". Abert (2007) wrote, "the most striking aspect of these dances is their almost literally inexhaustible fund of invention. Although their form offers only limited scope for experimentation, each dance differs from the others." Lindmayr-Brandl (2006) writes that "[the dances] that are accessible today, brought to life in the concert hall or in recordings, represent a precious treasure, the immediate expression of the joy of life." Mozart included a substantial ballet at the end of his opera