Question: Symphony No. 63 was composed by which Austrian Classical composer?

Context paragraphs:
Ezio Bosso: Ezio Bosso (13 September 1971) is an Italian composer, classical musician and conductor.  Born in Turin, Italy, Bosso learned to read and play music before the age of four.  At the age of 14, he became the bass player for the band Statuto.  Bosso later abandoned popular music, in order to become an orchestral conductor and classical composer.  He conducted such prominent orchestras as the London Symphony Orchestra.

Hans Redlich: Hans Ferdinand Redlich (11 February 1903 – 27 November 1968) was an Austrian classical composer, conductor, musicologist and writer.

Henryk Górecki: Henryk Mikołaj Górecki (; English pronunciation Go-RET-ski; December 6, 1933 – November 12, 2010) was a Polish composer of contemporary classical music.  According to critic Alex Ross, no recent classical composer has had as much commercial success as Górecki.  Górecki became a leading figure of the Polish avant-garde during the post-Stalin cultural thaw.  His Webernian-influenced serialist works of the 1950s and 1960s were characterized by adherence to dissonant modernism and drew influence from Luigi Nono, Karlheinz Stockhausen, Krzysztof Penderecki and Kazimierz Serocki.  He continued in this direction throughout the 1960s, but by the mid-1970s had changed to a less complex sacred minimalist sound, exemplified by the transitional Symphony No. 2 and the hugely popular Symphony No. 3 ("Symphony of Sorrowful Songs").  This later style developed through several other distinct phases, from such works as his 1979 "Beatus Vir", to the 1981 choral hymn "Miserere", the 1993 "Kleines Requiem für eine Polka" and his requiem "Good Night".

Artur Schnabel: Artur Schnabel (17 April 1882 – 15 August 1951) was an Austrian classical pianist, who also composed and taught.  Schnabel was known for his intellectual seriousness as a musician, avoiding pure technical bravura.  Among the 20th century's most respected and most important pianists, his playing displayed marked vitality, profundity and spirituality in the Austro-German classics, particularly the works of Beethoven and Schubert.  His performances of these compositions have often been hailed as models of interpretative penetration.  His best-known recording is of the complete Beethoven piano sonatas; recorded between 1932 and 1935, it is the first recording ever made of the complete cycle of 32 sonatas, leading Harold C. Schonberg to refer to Schnabel as "the man who invented Beethoven".

List of symphonies by Wolfgang Amadeus Mozart: This is a list of symphonies by the classical composer Wolfgang Amadeus Mozart.  Symphonies No.  2 (attributed to Leopold Mozart) and 3 (written by Carl Friedrich Abel) are spurious.  Spurious symphonies can be found at Mozart symphonies of spurious or doubtful authenticity.  Symphonies that are suspected to be not Mozart's, but have not been proven to be the work of another composer, are in this list.  Mozart's "37th symphony" is actually Michael Haydn's 25th symphony; Mozart only added a 20-bar slow introduction to it.

Tomáš Svoboda (composer): Tomáš Svoboda (born December 6, 1939) is a Czech-American contemporary classical composer and pianist, whose debut took place in Prague, Czechoslovakia on September 7, 1957, with the world premiere of his Symphony No. 1 ("Of Nature") with the FOK Prague Symphony conducted by Václav Smetáček.  Svoboda's catalog contains over 200 compositions, including 6 symphonies, 5 concerti.  His music is performed worldwide and recordings of more than 50 works have now been released.  Svoboda's Piano Trios CD recording received a 2001 "Critics Choice Award" from the American Record Guide and his Marimba Concerto received recognition in a 2003 Grammy Award nomination for the Oregon Symphony.

Symphony No. 63 (Haydn): The Symphony No. 63 in C major, Hoboken I/63, is a symphony by Joseph Haydn written sometime between 1779 and 1781.  It is often known by the title of the second movement, "La Roxelane", named for Roxelana, the influential wife of Suleiman the Magnificent of the Ottoman Empire.  This second movement was originally part of Haydn's incidental music for Charles Simon Favart's stage work "Soliman der zweite" (or "Les Trois Sultanes") in which Roxelana was a character.

Joseph Haydn: (Franz) Joseph Haydn ( ; ] ; 31 March 173231 May 1809) was an Austrian composer of the Classical period.  He was instrumental in the development of chamber music such as the piano trio and his contributions to musical form have earned him the epithets "Father of the Symphony" and "Father of the String Quartet".

Luise Walker: Luise Walker (9 September 1910 – 30 January 1998) was an Austrian classical guitarist and guitar composer – one of the most prominent female guitarists of her time.

Florian Magnus Maier: Florian Magnus Maier (born 1973), also known as Morean, is a German classical composer, guitarist, producer and vocalist of the bands Alkaloid, Dark Fortress, and Noneuclid.  Although born in Munich, he has resided in the Netherlands for over 20 years, his primary occupation being a composer and guitar player within both the contemporary classical and heavy metal communities.  Although mostly recognized within the metal community for his vocalist duties with black metal band Dark Fortress, Maier is also a vocalist and guitarist for progressive metal outfits Alkaloid and Noneuclid.  Being a classical composer, Maier has also collaborated with Devin Townsend and Paradise Lost on orchestrations.

Supporting paragraphs: Symphony No. 63 (Haydn) Joseph Haydn
Answer: Joseph Haydn