Question: Who is both the author of "A Treatise on the Fundamental Principles of Violin Playing" as well as the father of Wolfgang Amadeus Mozart?
Context: Amadeus is a 1984 American period drama film directed by Miloš Forman, adapted by Peter Shaffer from his stage play "Amadeus".  The story, set in Vienna, Austria, during the latter half of the 18th century, is a fictionalized biography of Wolfgang Amadeus Mozart.  Mozart's music is heard extensively in the soundtrack of the movie.  The film follows Italian composer Antonio Salieri at the court of Emperor Joseph II, and his jealous vendetta against his younger rival, Wolfgang Amadeus Mozart. "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 Violin Sonata in D major, K. deest, is a composition for violin and piano (or harpsichord) published in England during the 18th Century under the name of Wolfgang Amadeus Mozart.  It is typical of many such works intended for use by amateur musicians in a domestic setting, with the attribution to a well known composer being used to boost sales.  As with Mozart's earliest violin sonatas, the keyboard instrument is dominant. The Neue Mozart-Ausgabe (abbreviated as "NMA"; in English, "New Mozart Edition") is the second complete works edition of the music of Wolfgang Amadeus Mozart.  A longer and more formal title for the edition is "Wolfgang Amadeus Mozart.  Neue Ausgabe sämtlicher Werke." Sonata for Piano and Violin No. 21 in E minor, K. 304 (K300c) is a work by Wolfgang Amadeus Mozart.  It was composed in 1778 while Mozart was in Paris.  The piece was composed during the same period that Mozart's mother, Anna Maria Mozart, died, and the sonata's mood reflects this.  It is the only instrumental work by Mozart whose home key is E minor. Versuch einer gründlichen Violinschule ("A Treatise on the Fundamental Principles of Violin Playing") is a textbook for instruction in the violin, published by Leopold Mozart in 1756.  The work was influential in its day, and continues to serve as a scholarly source concerning 18th century performance practice. Johann Georg Leopold Mozart (November 14, 1719 – May 28, 1787) was a German composer, conductor, teacher, and violinist.  Mozart is best known today as the father and teacher of Wolfgang Amadeus Mozart, and for his violin textbook "Versuch einer gründlichen Violinschule". 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. The Alte Mozart-Ausgabe is the name by which the first complete edition of the music of Wolfgang Amadeus Mozart, is known nowadays, published by Breitkopf & Härtel from January 1877 to December 1883, with supplements published until 1910.  The name "Alte Mozart-Ausgabe" (abbreviated "AMA") is actually a modern invention to distinguish the edition from the second Mozart complete works edition, the "Neue Mozart-Ausgabe"; the publication title of Breitkopf & Härtel's edition was "Wolfgang Amadeus Mozarts Werke.  Kritisch durchgesehene Gesammtausgabe."  (It is therefore sometimes referred to as the ""Mozart Gesammtausgabe"".) Josef Mysliveček (9 March 1737 – 4 February 1781) was a Czech composer who contributed to the formation of late eighteenth-century classicism in music.  Mysliveček provided his younger friend Wolfgang Amadeus Mozart with significant compositional models in the genres of symphony, Italian serious opera, and violin concerto; both Wolfgang and his father Leopold Mozart considered him an intimate friend from the time of their first meetings in Bologna in 1770 until he betrayed their trust over the promise of an operatic commission for Wolfgang to be arranged with the management of the Teatro San Carlo in Naples.  He was close to the Mozart family, and there are frequent references to him in the Mozart correspondence.
Answer: Leopold Mozart