The piece of music once known as Wolfgang Amadeus Mozart's Symphony No. 2 in B♭ major, K. 17, is now considered to be not by him, but by possibly his father, Leopold Mozart. This symphony has been given the number Anhang C 11.02 in the sixth edition of Ludwig Ritter von Köchel's catalogue of Mozart's music., and is now also catalogued as Eisen B♭ 6 in Cliff Eisen's catalogue of Leopold Mozart's symphonies.
Symphony No. 14 in A major, K. 114, is a symphony composed by Wolfgang Amadeus Mozart on December 30, 1771, when Mozart was fifteen years old, and a fortnight after the death of the Archbishop Sigismund von Schrattenbach. The piece was written in Salzburg between the composer's second and third trips to Italy. Mozart was also influenced by J. C. Bach's "Italianate" style of composition."
Symphony No. 12 in G major, K. 110/75b, by Wolfgang Amadeus Mozart, was composed in Salzburg in the summer of 1771. The symphony was apparently prepared in anticipation of Mozart's second Italian journey, which was to take place between August and December 1771. The symphony is in four movements, the opening allegro being the longest movement that Mozart had written to that date. It is the first of a group of works "painted on a larger canvas and achieving a greater individuality than his earlier exuberant pieces".
Symphony No. 13 in F major, K. 112, by Wolfgang Amadeus Mozart, was written in Milan during his second journey to Italy in the autumn of 1771. The symphony is in four movements, the second of which is scored for strings alone. The third movement minuet may have been written earlier, and then incorporated into the symphony—the autograph manuscript shows the minuet copied in Leopold's hand. Nicholas Kenyon describes Symphony No. 13 as the last in "conventional mode"—thereafter "we are in the beginnings of a different world."
This list of Mozart symphonies of spurious or doubtful authenticity contains 39 symphonic works whose initial attribution to Wolfgang Amadeus Mozart has subsequently been proved spurious, or is the subject of continuing doubt. The number of symphonies actually written by Mozart is imprecisely known; of the 41 formally numbered, three are established as by other composers and another, No. 11, is considered by scholars to be of uncertain authenticity. Outside the accepted sequence 1–41, however, there are around twenty other genuine Mozart symphonies, and beyond these, a larger number of problematic works which have not been authenticated as Mozart's. Some of these may be genuine; dubious works are often treated as authentic by the compilers of collected editions—eight are in the main body of the 1991 Neue Mozart-Ausgabe, and another two are included in the supplementary 2000 volume of works of doubtful authenticity. Some, however, have long been accepted as the works of other composers, who in many instances have been positively identified.
The six string quartets, K. 155–160, were composed by Wolfgang Amadeus Mozart in late 1772 and early 1773 when Mozart was sixteen and seventeen years of age. Because they were composed in Milan while he was working on his opera Lucio Silla, they are popularly known as the Milanese Quartets. Before this set was composed, Mozart had written one earlier string quartet, so these six quartets are ordinally numbered from No. 2 to No. 7. The quartets are written in a plan of keys of D-G-C-F-B♭-E♭ following the circle of fifths.
The Symphony in F major "No. 42", K. 75, was written by Wolfgang Amadeus Mozart probably around March to August 1771 in Salzburg.
The Symphony in F major "No. 43", K. 76/42a, was probably written by Wolfgang Amadeus Mozart.
The Symphony in D major "No. 48", K. 111+120, was composed by Wolfgang Amadeus Mozart in 1771. The first two movements are from the overture to the opera Ascanio in Alba, K. 111, and the last movement, K. 120/111a, was composed separately.
The Symphony in D major "No. 50", K. 161/141a, was composed by Wolfgang Amadeus Mozart in 1772. The first two movements are from the overture to the opera Il sogno di Scipione, K. 126, and the last movement, K. 163, was composed separately. Köchel gave the entire work the number K. 161.
The Symphony in D major "No. 51", K. 196+121, was composed by Wolfgang Amadeus Mozart in 1774–1775. The first two movements are from the overture to the opera La finta giardiniera, K. 196, and the last movement, K. 121/207a, was composed separately in 1775.
The Symphony in C major "No. 52", K. 208+102, was composed by Wolfgang Amadeus Mozart in 1775. The first two movements are from the opera Il re pastore, K. 208, and the last movement, K. 102/213c, were composed separately. The movements are played one after another without a break.
The Symphony in B♭ major "No. 55", K. Anh. 214/45b, was probably written by Wolfgang Amadeus Mozart in early 1768 in Salzburg.
The Symphony in D major "No. 45", K. 95/73n, was probably written by Wolfgang Amadeus Mozart in 1770 in Rome.
The Symphony in D major "No. 47", K. 97/73m, was probably written by Wolfgang Amadeus Mozart in 1770 in Rome.
The Symphony in F major "No. 56", K. 98/Anh.C 11.04, was once thought to have been written by Wolfgang Amadeus Mozart, but today is regarded as spurious. As of 2009, it is the only one of Mozart's symphonies published in the Alte Mozart-Ausgabe that has never been recorded. It is not included in the Neue Mozart-Ausgabe.
The Symphony in D major "No. 44", K. 81/73l, may have been written by Wolfgang Amadeus Mozart in 1770 in Rome, although it has sometimes also been attributed to his father Leopold Mozart.
The Symphony in B♭ major "No. 54", K. Anh. 216/74g/Anh.C 11.03, may have been written by Wolfgang Amadeus Mozart in 1771, in Salzburg.
The Symphony in A minor "Odense", K. Anh. 220/16a, was formerly attributed to Wolfgang Amadeus Mozart. If the Odense Symphony had truly been Mozart's, it would be among only three of Mozart's symphonies to be written in a minor key. It is now considered certain that the symphony is not by Mozart.
