Question: Who was the father of the composer of Piano Sonata No. 1?

full_context: Document 1: 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 2: 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 3: Piano Sonata No. 9 (Mozart): Wolfgang Amadeus Mozart's Piano Sonata No. 9 in D major, K. 311 / 284c, was written on the composer's stay in Augsburg and Mannheim in November-December 1777, and is contemporaneous with his Sonata K. 309 (Mozart wrote his Sonata K. 310 in the summer of the following year, in Paris). The three sonatas K. 309–311 were published as a set 'Opus IV' in about 1782, by Franz Joseph Heina in Paris.
Document 4: 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 5: Piano Sonata No. 8 (Mozart): Wolfgang Amadeus Mozart's Piano Sonata No. 8 in A minor, K. 310 / 300d, was written in 1778. The sonata is the first of only two Mozart piano sonatas in a minor key (the other being No. 14 in C minor, K. 457). It was composed in the summer of 1778 around the time of his mother's death, one of the most tragic times of his life.
Document 6: Luigi Gatti: Luigi Gatti (October 7, 1740 – March 1, 1817) was a classical composer. He was born in Lazise in 1740, the son of an organist, Francesco della Gatta. He was ordained a priest in Mantua. In the 1780s he became Hofkapellmeister in Salzburg and Leopold Mozart showed his irritation at not receiving it himself. Between 1801 and 1804 Gatti helped Mozart's sister, Nannerl to locate unknown pieces by Mozart. He died in Salzburg in 1817.
Document 7: 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 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: Piano Sonata No. 6 (Mozart): Wolfgang Amadeus Mozart's Piano Sonata No. 6 in D major, K. 284 / 205b, (1775) is a sonata in three movements:
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: 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 12: Piano Sonata No. 1 (Mozart): Wolfgang Amadeus Mozart's Piano Sonata No. 1 in C major, K. 279 / 189d (1774), is a piano sonata in three movements. It was written down, except for the first part of the opening movement, during the visit Mozart paid to Munich for the production of "La finta giardiniera" from late 1774 to the beginning of the following March. A typical performance of the sonata takes about 14 minutes. It is the first of his 18 piano sonatas. All but two of the sonatas, No. 8 in A minor and No. 14 in C minor, are in a major key. Also, the first six sonatas seem to follow the cycle of fifths, to the flat side first (No. 1 in C major, No. 2 in F major, No. 3 in B-flat major, No. 4 in E-flat major) and then to the sharp side (No. 5 in G major, No. 6 in D major).
Document 13: Violin Sonata No. 35 (Mozart): It is the last of Mozart's substantial violin sonatas, with the only remaining work he wrote for this combination, the sonata in F, K. 547 of 1788 being more of a sonatina. It is also considered by several authors, including Alfred Einstein, to be part of his last series of three great violin sonatas which starts with the Regina Strinasacchi sonata in B-flat K. 454 from 1784 (his annus mirabilis, the year also of the six great piano concertos 14 – 19 and the quintet for piano and winds) and continuing with the E-flat violin sonata from December 1785. The first movement is a movement in sonata form in 6/8 time, with more evenly divided contributions between the two instruments than in the earliest of his sonatas, an exposition divided between its two tonal groups (A and E major), and a compact but unwasteful development section.
Document 14: Piano Sonata No. 17 (Mozart): Wolfgang Amadeus Mozart's Piano Sonata No. 17 in B major, K. 570, dated February 1789, is a sonata in three movements:
Document 15: Piano Concertos Nos. 1–4 (Mozart): Wolfgang Amadeus Mozart began his series of preserved piano concertos with four that he wrote at the age of 11, in Salzburg: K. 37 and 39–41. The autographs, all held by the Jagiellonian Library, Kraków, are dated by his father as having been completed in April (K. 37) and July (K. 39–41) of 1767. Although these works were long considered to be original, they are now known to be orchestrations of sonatas by various German virtuosi. The works on which the concertos are based were largely published in Paris, and presumably Mozart and his family became acquainted with them or their composers during their visit to Paris in 1763–64.
ground_truth: Leopold Mozart
sub_queries: Piano Sonata No. 1 >> composer Answer: Wolfgang Amadeus Mozart
Who was the dad of Wolfgang Amadeus Mozart ? Answer: Leopold Mozart