Question: What is the main subject of biographies of the person who expanded the single reeds role?

full_context: Document 1: Symphony, K. 45b (Mozart): This work was only known to Ludwig Ritter von Köchel as an incipit in the catalogue of Breitkopf & Härtel, and thus it was placed in the Anhang as K. Anh. 214. Alfred Einstein then discovered a set of parts in the Berlin State Library with the title ""Synfonia Ex Bb...Del Sigr. cavaliere Amadeo Wolfgango Mozart Maestro di concerto di S.A. á Salisburgo"". Wolfgang became the Concertmaster to the Archbishop of Salzburg in November 1769, and was given the title "cavaliere" in July 1770, but as this is a later copy, this information cannot be used for dating purposes. Einstein believed the symphony to date from early 1768 on stylistic grounds; Neal Zaslaw and Gerhard Allroggen believe even earlier dates to also be possible, and Zaslaw dated the symphony cautiously to Salzburg in 1767. Einstein also believed that the symphonies in the catalogue of Breitkopf & Härtel were sent by Leopold Mozart to be published.
Document 2: Classical music: Classical musicians continued to use many of instruments from the Baroque era, such as the cello, contrabass, recorder, trombone, timpani, fortepiano and organ. While some Baroque instruments fell into disuse (e.g., the theorbo and rackett), many Baroque instruments were changed into the versions that are still in use today, such as the Baroque violin (which became the violin), the Baroque oboe (which became the oboe) and the Baroque trumpet, which transitioned to the regular valved trumpet.
Document 3: Classical music: Wind instruments became more refined in the Classical era. While double reeded instruments like the oboe and bassoon became somewhat standardized in the Baroque, the clarinet family of single reeds was not widely used until Mozart expanded its role in orchestral, chamber, and concerto settings.
Document 4: Biographies of Mozart: Wolfgang Amadeus Mozart died after a short illness on 5 December 1791, aged 35. His reputation as a composer, already strong during his lifetime, rose rapidly in the years after his death, and he became (as he has remained to this day) one of the most celebrated of all composers.
Document 5: Classical music: Although Classical music in the 2000s has lost most of its tradition for musical improvisation, from the Baroque era to the Romantic era, there are examples of performers who could improvise in the style of their era. In the Baroque era, organ performers would improvise preludes, keyboard performers playing harpsichord would improvise chords from the figured bass symbols beneath the bass notes of the basso continuo part and both vocal and instrumental performers would improvise musical ornaments. J.S. Bach was particularly noted for his complex improvisations. During the Classical era, the composer-performer Mozart was noted for his ability to improvise melodies in different styles. During the Classical era, some virtuoso soloists would improvise the cadenza sections of a concerto. During the Romantic era, Beethoven would improvise at the piano. For more information, see Improvisation.
Document 6: Classical music: During the Baroque era, keyboard music played on the harpsichord and pipe organ became increasingly popular, and the violin family of stringed instruments took the form generally seen today. Opera as a staged musical drama began to differentiate itself from earlier musical and dramatic forms, and vocal forms like the cantata and oratorio became more common. Vocalists began adding embellishments to melodies. Instrumental ensembles began to distinguish and standardize by size, giving rise to the early orchestra for larger ensembles, with chamber music being written for smaller groups of instruments where parts are played by individual (instead of massed) instruments. The concerto as a vehicle for solo performance accompanied by an orchestra became widespread, although the relationship between soloist and orchestra was relatively simple.
Document 7: Wolfgang Amadeus Mozart: Wolfgang Amadeus Mozart was born on 27January 1756 to Leopold Mozart (1719–1787) and Anna Maria, née Pertl (1720–1778), at 9 Getreidegasse in Salzburg. This was the capital of the Archbishopric of Salzburg, an ecclesiastic principality in what is now Austria, then part of the Holy Roman Empire. He was the youngest of seven children, five of whom died in infancy. His elder sister was Maria Anna Mozart (1751–1829), nicknamed "Nannerl". Mozart was baptised the day after his birth, at St. Rupert's Cathedral in Salzburg. The baptismal record gives his name in Latinized form, as "Joannes Chrysostomus Wolfgangus Theophilus Mozart". He generally called himself "Wolfgang Amadè Mozart" as an adult, but his name had many variants.
Document 8: Wolfgang Amadeus Mozart: Wolfgang Amadeus Mozart (/ ˈwʊlfɡæŋ æməˈdeɪəs ˈmoʊtsɑːrt / MOHT - sart; German: (ˈvɔlfɡaŋ amaˈdeːʊs ˈmoːtsaʁt); 27 January 1756 -- 5 December 1791), baptised as Johannes Chrysostomus Wolfgangus Theophilus Mozart, was a prolific and influential composer of the Classical era.
Document 9: Classical music: The Classical era, from about 1750 to 1820, established many of the norms of composition, presentation, and style, and was also when the piano became the predominant keyboard instrument. The basic forces required for an orchestra became somewhat standardized (although they would grow as the potential of a wider array of instruments was developed in the following centuries). Chamber music grew to include ensembles with as many as 8 to 10 performers for serenades. Opera continued to develop, with regional styles in Italy, France, and German-speaking lands. The opera buffa, a form of comic opera, rose in popularity. The symphony came into its own as a musical form, and the concerto was developed as a vehicle for displays of virtuoso playing skill. Orchestras no longer required a harpsichord (which had been part of the traditional continuo in the Baroque style), and were often led by the lead violinist (now called the concertmaster).
Document 10: Classical music: The "standard complement" of double winds and brass in the orchestra from the first half of the 19th century is generally attributed to Beethoven. The exceptions to this are his Symphony No. 4, Violin Concerto, and Piano Concerto No. 4, which each specify a single flute. The composer's instrumentation usually included paired flutes, oboes, clarinets, bassoons, horns and trumpets. Beethoven carefully calculated the expansion of this particular timbral "palette" in Symphonies 3, 5, 6, and 9 for an innovative effect. The third horn in the "Eroica" Symphony arrives to provide not only some harmonic flexibility, but also the effect of "choral" brass in the Trio. Piccolo, contrabassoon, and trombones add to the triumphal finale of his Symphony No. 5. A piccolo and a pair of trombones help deliver "storm" and "sunshine" in the Sixth. The Ninth asks for a second pair of horns, for reasons similar to the "Eroica" (four horns has since become standard); Beethoven's use of piccolo, contrabassoon, trombones, and untuned percussion—plus chorus and vocal soloists—in his finale, are his earliest suggestion that the timbral boundaries of symphony should be expanded. For several decades after he died, symphonic instrumentation was faithful to Beethoven's well-established model, with few exceptions.
Document 11: Classical music: Baroque instruments included some instruments from the earlier periods (e.g., the hurdy-gurdy and recorder) and a number of new instruments (e.g, the cello, contrabass and fortepiano). Some instruments from previous eras fell into disuse, such as the shawm and the wooden cornet. The key Baroque instruments for strings included the violin, viol, viola, viola d'amore, cello, contrabass, lute, theorbo (which often played the basso continuo parts), mandolin, cittern, Baroque guitar, harp and hurdy-gurdy. Woodwinds included the Baroque flute, Baroque oboe, rackett, recorder and the bassoon. Brass instruments included the cornett, natural horn, Baroque trumpet, serpent and the trombone. Keyboard instruments included the clavichord, tangent piano, the fortepiano (an early version of the piano), the harpsichord and the pipe organ. Percussion instruments included the timpani, snare drum, tambourine and the castanets.
Document 12: Symphony No. 41 (Mozart): Wolfgang Amadeus Mozart completed his Symphony No. 41 in C major, K. 551, on 10 August 1788. The longest and last symphony that he composed, it is regarded by many critics as among the greatest symphonies in classical music.
Document 13: Classical music: The Classical era stringed instruments were the four instruments which form the string section of the orchestra: the violin, viola, cello and contrabass. Woodwinds included the basset clarinet, basset horn, clarinette d'amour, the Classical clarinet, the chalumeau, the flute, oboe and bassoon. Keyboard instruments included the clavichord and the fortepiano. While the harpsichord was still used in basso continuo accompaniment in the 1750s and 1760s, it fell out of use in the end of the century. Brass instruments included the buccin, the ophicleide (a serpent replacement which was the precursor of tuba) and the natural horn.
Document 14: Franz Xaver Wolfgang Mozart: Franz Xaver Wolfgang Mozart (26 July 1791 – 29 July 1844), also known as Wolfgang Amadeus Mozart, Jr., was the youngest child of six born to Wolfgang Amadeus Mozart and his wife Constanze. He was the younger of his parents' two surviving children. He was a composer, pianist, conductor, and teacher from the late classical period whose musical style was of an early Romanticism, heavily influenced by his father's mature style.
Document 15: Mozart's birthplace: Mozart's birthplace (German: ' or ') was the birthplace of Wolfgang Amadeus Mozart at No. 9 Getreidegasse in Salzburg, Austria. The Mozart family resided on the third floor from 1747 to 1773. Mozart himself was born here on 27 January 1756. He was the seventh child of Leopold Mozart, who was a musician of the Salzburg Royal Chamber.
ground_truth: Wolfgang Amadeus Mozart
sub_queries: Who expanded the single reeds role? Answer: Mozart
Biographies of Mozart >> main subject Answer: Wolfgang Amadeus Mozart