Question: "This is a mostly complete list of the works of Wolfgang Amadeus Mozart", according to the sixth edition of the Köchel catalogue, Mozart, was baptised as Johannes Chrysostomus Wolfgangus Theophilus Mozart, was a prolific and influential composer of which era?

Context articles: Alfred Einstein
Piano Concerto No. 11 (Mozart)
Symphony No. 2 (Mozart)
Mozart's Twelfth Mass, K. Anh. 232
Symphony No. 6 (Mozart)
Köchel catalogue
Adélaïde Concerto
Wolfgang Amadeus Mozart
Flute Quartet No. 3 (Mozart)
Piano Concerto No. 19 (Mozart)

Alfred Einstein (December 30, 1880February 13, 1952) was a German-American musicologist and music editor.
 He is best known for being the editor of the first major revision of the Köchel catalogue, which was published in the year 1936.
 The Köchel catalogue is the extensive catalogue of the works of Wolfgang Amadeus Mozart.
Mozart's Piano Concerto No. 11 in F major, K.
 413 (K. 387a in the sixth edition of the Köchel catalogue), was the second of the group of three early concertos he wrote when in Vienna, in the autumn of 1782 (according to the latest edition of the Köchel catalogue, K. 414 was written first).
 It was the first full concerto he wrote for the subscription concerts he gave in the city.
 The autograph is held by the Jagiellońska Library, Kraków with an additional, now incomplete, copy that Mozart brought to Salzburg in 1783, in the library of the Archabbey of St Peter's, Salzburg.
 The concerto is in the usual three movements:
The piece of music once known as Wolfgang Amadeus Mozart's Symphony No. 2 in B♭ major, KV 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 catalog of Mozart's music.
 , and is now also catalogued as Eisen B♭ 6 in Cliff Eisen's catalog of Leopold Mozart's symphonies.
Mozart's Twelfth Mass, once a top seller among the liturgical compositions published by Vincent Novello in the 19th century, is a work no longer attributed to Wolfgang Amadeus Mozart.
 Köchel rejected the attribution to Mozart in the Anhang (appendix) of the first edition of his catalogue of Mozart's works, there listed as K. Anh.
 232, and in later editions as K. Anh.
 C1.04.
Symphony No. 6 in F major, K. 43, was composed by Wolfgang Amadeus Mozart in 1767.
 According to Alfred Einstein in his 1937 revision of the Köchel catalogue, the symphony was probably begun in Vienna and completed in Olomouc, a Moravian town to which the Mozart family fled to escape a Viennese smallpox epidemic; see Mozart and smallpox.
"This is a mostly complete list of the works of Wolfgang Amadeus Mozart, according to the sixth edition of the Köchel catalogue.
 For a selective list of his works, grouped by genre, see List of compositions by Wolfgang Amadeus Mozart".
The Adélaïde Concerto is the nickname of a Violin Concerto in D major attributed to Wolfgang Amadeus Mozart and given the catalogue number K. Anh.
 294a in the third edition of the standard Köchel catalogue of Mozart's works.
 Unknown until the 20th century, this concerto was later discovered to be a spurious work by Marius Casadesus.
 It was given a new number in the sixth edition of the Köchel catalogue, K. Anh.C 14.05, as part of the Anhang C designated for spurious or doubtful works which have been attributed to Mozart at some time.
Wolfgang Amadeus Mozart ( ; ; ] ; 27 January 1756 – 5 December 1791), baptised as Johannes Chrysostomus Wolfgangus Theophilus Mozart, was a prolific and influential composer of the Classical era.
Wolfgang Amadeus Mozart's Flute Quartet No. 3 in C major, K. 285b, is the last of three quartets for the amateur flautist Ferdinand De Jean.
 Mozart's manuscript designates this work for flute, violin, viola and basso.
 Despite following directly after the first two flute quartets in the Köchel catalogue, the Quartet in C was almost certainly written a few years later, likely sometime between the years 1781 to 1782.
The Piano Concerto No. 19 in F major, KV 459 by Wolfgang Amadeus Mozart was written at the end of 1784: Mozart's own catalogue of works records that it was completed on 11 December (works surrounding it in the Köchel catalogue are KV 458, the "Hunt" quartet and KV 464, the fifth of the Haydn set).
 It is occasionally known as the "second coronation concerto" on account of Mozart playing it on the occasion of the coronation of Leopold II in Frankfurt am Main in October 1790.
 The autograph is held by the Jagiellońska Library, Kraków.
 The first edition was produced by Johann Andre of Offenbach in 1794, and Breitkopf & Härtel produced an edition in 1800.
 Like most of Mozart's concertos it is in three movements: