Question: What is the main subject of biograhies of the composer of Betulia liberata?

full_context: Document 1: Betulia liberata: The Mozart is the best known, if only because the composer's output receives more examination. Composed in March to July 1771 when Mozart was 15 years old, K. 118 (74c) is a 140-minute "azione sacra" on a text by Metastasio tracing the story of Judith and Holofernes from the biblical "". It was commissioned in March 1771 by Giuseppe Ximenes, Prince of Aragon, while Mozart and his father Leopold were on the way home to Salzburg from their first journey to Italy. It is the only oratorio Mozart ever wrote. Its two parts comprise sixteen arias, with solo or choral parts, scored for soloists, choir and orchestra. Not performed in Mozart's lifetime, "La Betulia liberata" is shaped stylistically to works by Leonardo Leo and Johann Adolph Hasse.
Document 2: 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.
Document 3: 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 4: Piece in F for Keyboard, K. 33B (Mozart): Mozart wrote this piece in pencil on the back of a circular by the Zürcher Musikkollegium (Zürich Music College) dated 30 September 1766, when the Mozart family came to the end of their Grand Tour. The circular invited sponsors, music lovers and other people who might be interested to concerts by "the young (9 years old) Master Mozart as well as his maiden sister" (Maria Anna – Nannerl) on October 7 and 9. It can be assumed that Mozart played or improvised this lively piece in one of those concerts, the programs to which are lost. Mozart wrote it on the back of the circular probably as a souvenir for the College's board; otherwise he would have used his sister's notebook or his third book of sketches (""), which is also lost. The autograph became known very late (in 1942), and so is missing from Alfred Einstein's 3rd edition of the Köchel catalogue.
Document 5: Bastien und Bastienne: Although he was very young, Mozart already had excellent vocal writing skills and a knack for parody and whimsy which would reach full flower in his later works. "" is possibly the easiest to perform of Mozart's juvenile works.
Document 6: Classical period (music): However, Vienna's fall as the most important musical center for orchestral composition during the late 1820s, precipitated by the deaths of Beethoven and Schubert, marked the Classical style's final eclipse -- and the end of its continuous organic development of one composer learning in close proximity to others. Franz Liszt and Frédéric Chopin visited Vienna when they were young, but they then moved on to other cities. Composers such as Carl Czerny, while deeply influenced by Beethoven, also searched for new ideas and new forms to contain the larger world of musical expression and performance in which they lived.
Document 7: Piano Sonata No. 14 (Mozart): The piano sonata was composed during the approximately 10-year period of Mozart's life as a freelance artist in Vienna after he removed himself from the patronage of the Archbishop of Salzburg in 1781. It is one of the earliest of only six sonatas composed during the Vienna years, and was probably written either as a teaching tool or for personal use. Sonatas during this time were generally written for the domestic sphere – as opposed to a symphony or concerto, they were designed to convey ideas in a small, intimate setting.
Document 8: 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 9: 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 10: 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 11: Il re pastore: Metastasio wrote the libretto in 1751, basing it on a work by Torquato Tasso called "Aminta". The libretto was picked up when Mozart (just 19 at the time) and his father saw a performance of it set to music composed by Felice Giardini – Mozart's version, however was two acts rather than Giardini's three, and has a few substantial changes. Each act lasts for around an hour in performance. The Salzburg court chaplain Varesco was largely responsible for this editing of Metastasio's libretto.
Document 12: 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 13: Solomon (Handel): Solomon, HWV 67, is an English oratorio by George Frideric Handel. The anonymous libretto – currently thought to have been penned by the English Jewish poet/playwright Moses Mendes (d.1758) – is based on the biblical stories of the wise king Solomon from the First Book of Kings and the Second Book of Chronicles, with additional material from "Antiquities of the Jews" by ancient historian Flavius Josephus. The music was composed between 5 May and 13 June 1748, and the first performance took place on 17 March 1749, with Caterina Galli in the title role at the Covent Garden Theatre in London, where it had two further performances. Handel revived the work in 1759.
Document 14: 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 15: Mitridate, re di Ponto: Mozart wrote "Mitridate" while touring Italy in 1770. The musicologist Daniel E. Freeman has recently demonstrated that it was composed with close reference to the opera "La Nitteti" by Josef Mysliveček. The latter was the opera being prepared for production in Bologna when Mozart met Mysliveček for the first time with his father in March 1770. Mysliveček visited the Mozarts frequently in Bologna during the summer of 1770 while Wolfgang was working on "Mitridate". Mozart gained expertise in composition from his older friend and also incorporated some of his musical motives into his own operatic setting. The opera was first performed at the Teatro Regio Ducal, Milan, on 26 December 1770 (at the Milan Carnival). It was a success, having been performed twenty-one times despite doubts because of Mozart's extreme youth – he was 14 at the time. No revival took place until the 20th century. This opera features virtuoso arias for the principal roles, but only two ensemble numbers: the act 2 ending duet between Aspasia and Sifare ("Se viver non degg’io"), and the brief quintet that ends the opera, very characteristic of standard baroque opera seria where the opera ends with a short "coro" or "tutti" number.
ground_truth: Wolfgang Amadeus Mozart
sub_queries: Betulia liberata >> composer Answer: Mozart
Biographies of Mozart >> main subject Answer: Wolfgang Amadeus Mozart