in the ascendent: simple, light music with a mania for cadencing; an emphasis on tonic, dominant, and subdominant to the exclusion of other harmonies; symmetrical phrases; and clearly articulated partitions in the overall form of movements. Some of Mozart's early symphonies are Italian overtures, with three movements running into each other; many are homotonal (all three movements having the same key signature, with the slow middle movement being in the relative minor). Others mimic the works of J. C. Bach, and others show the simple rounded binary forms turned out by Viennese composers. As Mozart matured, he progressively incorporated more features adapted from the Baroque. For example, the Symphony No. 29 in A major K. 201 has a contrapuntal main theme in its first movement, and experimentation with irregular phrase lengths. Some of his quartets from 1773 have fugal finales, probably influenced by Haydn, who had included three such finales in his recently published Opus 20 set. The influence of the Sturm und Drang ("Storm and Stress") period in music, with its brief foreshadowing of the Romantic era, is evident in the music of both composers at that time. Mozart's Symphony No. 25 in G minor K. 183 is another excellent example. Mozart would sometimes switch his focus between operas and instrumental music. He produced operas in each of the prevailing styles: opera buffa, such as The Marriage of Figaro, Don Giovanni, and Così fan tutte; opera seria, such as Idomeneo; and Singspiel, of which Die Zauberflöte is the most famous example by any composer. In his later operas, he employed subtle changes in instrumentation, orchestral texture, and tone colour, for emotional depth and to mark dramatic shifts. Here his advances in opera and instrumental composing interacted: his increasingly sophisticated use of the orchestra in the symphonies and concertos influenced his operatic orchestration, and his developing subtlety in using the orchestra to psychological effect in his operas was in turn reflected in his later non-operatic compositions. Köchel catalogue For unambiguous identification of works by Mozart, a Köchel catalogue number is used. This is a unique number assigned, in regular chronological order, to every one of his known works. A work is referenced by the abbreviation "K." or "KV" followed by this number. The first edition of the catalogue was completed in 1862 by Ludwig von Köchel. It has since been repeatedly updated, as scholarly research improves knowledge of the dates