Question: When was the Austrian composer who composed The String Quartet No. 5 (D 68) in B-flat major born 

Context paragraphs:
Quartet Movement in B-flat major (Tchaikovsky): The Quartet Movement in B-flat major, TH 110, also referred to as String Quartet in B-flat major or String Quartet Movement in B-flat major, by Pyotr Ilyich Tchaikovsky is believed to be only surviving movement of his first attempt to compose a string quartet.

String Quartet No. 5 (Shostakovich): Dmitri Shostakovich's String Quartet No. 5 in B-flat major (Op. 92) was composed in autumn 1952.  It was premiered in Leningrad in November 1953 by the Beethoven Quartet, to whom it is dedicated.

String Quartets (Schoenberg): The Austrian composer Arnold Schoenberg published four string quartets, distributed over his lifetime.  These were the String Quartet No. 1 in D minor, Op. 7 (1905), String Quartet No. 2 in F sharp minor, Op. 10 (1908), String Quartet No. 3, Op. 30 (1927), and the String Quartet No. 4, Op. 37 (1936).

Twelve Concertos, Op. 7 (Vivaldi): A set of twelve concertos was published by Estienne Roger in 1716-1717 under Antonio Vivaldi's name, as his Opus 7.  They were in two volumes, each containing concertos numbered 1-6.  Of the set, ten were for violin solo; the other two were for oboe solo.  The authenticity of some of the works included has long been doubted by scholars.  Three are now considered spurious (i.e. not in fact by Vivaldi) for stylistic reasons.  They are: No. 1 in B-flat major for oboe, RV Anh.  143 (formerly RV 465); No. 7 in B-flat major for oboe, RV Anh.  142 (formerly RV 464); and No. 9 in B-flat major for violin, RV Anh.  153 (formerly RV 373).

Jasper String Quartet: The Jasper String Quartet is a professional string quartet based in Philadelphia, Pennsylvania.  Currently the Ensemble in Residence at Temple University's Center for Gifted Young Musicians, the quartet was previously the Quartet in Residence at Oberlin Conservatory (from 2010-2012).  Formed in 2004 while its members were in school at Oberlin Conservatory, the quartet completed string quartet master's programs at Rice University (2006-2008) and Yale University (2008-2010).  The group's primary mentors are James Dunham, Norman Fischer and the Tokyo String Quartet.  In 2010, they joined the roster of Astral Artists.

String Quartet No. 1 (Hill): String Quartet No. 1 in B-flat major "Maori Quartet", Stiles 1.2.3.3 SQ1 is the first of Alfred Hill's seventeen string quartets.  Its composition began before 1892, it was completed after 1896 and premiered only on 18 May 1911 in Sydney.

String Quartet No. 5 (Schubert): The String Quartet No. 5 (D 68) in B-flat major was composed by Franz Schubert in 1813.

String Quartet No. 6 (Bartók): The String Quartet No. 6, Sz.  114, BB 119, was the final string quartet that Béla Bartók wrote before his death.  It was begun in August 1939 in Saanen, Switzerland, where Bartók was a guest of his patron, the conductor Paul Sacher.  Shortly after he completed the Divertimento for String Orchestra on the 17th, he started on a commission for his friend, the violinist Zoltán Székely.  Székely was acting as intermediary for the "New Hungarian Quartet", who had given the Budapest premiere of the String Quartet No. 5.  With the outbreak of World War II and his mother's illness, Bartók returned to Budapest, where the quartet was finished in November.  After his mother's death, Bartók decided to leave with his family for the United States.  Due to the difficulties of the war, communication between Bartók and Székely was difficult, and the quartet was not premiered until 20 January 1941, when the Kolisch Quartet, to whom the work is dedicated, gave its premiere at the Town Hall in New York City.

Ezequiel Viñao: Ezequiel Viñao (born 1960 in Buenos Aires) is an Argentine-American composer.  He emigrated to the United States in 1980 and studied at the Juilliard School.  His compositions include "La Noche de las Noches" (1989) for string quartet and electronics, which won First Prize at UNESCO's Latin-American Rostrum of Composers in 1993; six "Études" (1993) for piano solo, which were awarded a Kennedy Center Friedheim Award in 1995; a second string quartet "The Loss and the Silence" (2004), commissioned by the Juilliard String Quartet; "The Wanderer" (2005) for a cappella voices, commissioned by Chanticleer and Chicago a cappella, and "Sirocco Dust" (2009), commissioned by the Library of Congress for the St. Lawrence String Quartet.  He currently resides in New York City.

Franz Schubert: Franz Peter Schubert (] ; 31 January 179719 November 1828) was an Austrian composer.

Supporting paragraphs: String Quartet No. 5 (Schubert) Franz Schubert
Answer: 31 January 179719