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
Piano concertos by Wolfgang Amadeus Mozart given by Cliff Eisen in 1997 is: Cadenzas to at least K. 466 and 467 also possibly existed. These cadenzas are part of the public domain and can be accessed here: http://imslp.org/wiki/36_Cadenzas,_K.624_%28Mozart,_Wolfgang_Amadeus%29 Piano concertos by Wolfgang Amadeus Mozart Wolfgang Amadeus Mozart wrote 23 original concertos for piano and orchestra. These works, many of which Mozart composed for himself to play in the Vienna concert series of 1784–86, held special importance for him. For a long time relatively neglected, they are recognised as among his greatest achievements. They were championed by Donald Francis Tovey in his "Essay on the Classical Concerto"