Question:
Barack Hussein Obama II ( ( listen); born August 4, 1961) is an American politician who served as the 44th President of the United States from 2009 to 2017. The first African American to assume the presidency, he was previously the junior United States Senator from Illinois from 2005 to 2008. Before that, he served in the Illinois State Senate from 1997 until 2004. Obama was born in 1961 in Honolulu, Hawaii, two years after the territory was admitted to the Union as the 50th state.
Obama was born on August 4, 1961, at Kapiolani Medical Center for Women and Children in Honolulu, Hawaii. He is the only President who was born in Hawaii and the only President who was born outside of the contiguous 48 states. He was born to a white mother and a black father. His mother, Ann Dunham (1942-1995), was born in Wichita, Kansas; she was mostly of English descent, with some German, Irish, Scottish, Swiss, and Welsh ancestry. His father, Barack Obama Sr. (1936-1982), was a married Luo Kenyan man from Nyang'oma Kogelo. Obama's parents met in 1960 in a Russian language class at the University of Hawaii at Manoa, where his father was a foreign student on scholarship. The couple married in Wailuku, Hawaii on February 2, 1961, six months before Obama was born. In late August 1961 (only a few weeks after he was born), Barack and his mother moved to the University of Washington in Seattle, where they lived for a year. During that time, the elder Obama completed his undergraduate degree in economics in Hawaii, graduating in June 1962. He then left to attend graduate school on a scholarship at Harvard University, where he earned an M.A. in economics. Obama's parents divorced in March 1964. Obama Sr. returned to Kenya in 1964, where he married for a third time. He visited his son in Hawaii only once, at Christmas time in 1971, before he was killed in an automobile accident in 1982, when Obama was 21 years old. Recalling his early childhood, Obama said, "That my father looked nothing like the people around me - that he was black as pitch, my mother white as milk - barely registered in my mind." He described his struggles as a young adult to reconcile social perceptions of his multiracial heritage. In 1963, Dunham met Lolo Soetoro at the University of Hawaii; he was an Indonesian East-West Center graduate student in geography. The couple married on Molokai on March 15, 1965. After two one-year extensions of his J-1 visa, Lolo returned to Indonesia in 1966. His wife and stepson followed sixteen months later in 1967. The family initially lived in a Menteng Dalam neighborhood in the Tebet subdistrict of south Jakarta. From 1970, they lived in a wealthier neighborhood in the Menteng subdistrict of central Jakarta.
Answer this question using a quote from the text above:

what did he study?

Answer:
economics.

input: The choir is the modern-day descendant of the boys' choirs of the Viennese Court, dating back to the late Middle Ages. The choir was, for practical purposes, established by a letter from Emperor Maximilian I of Habsburg on 30 June 1498, instructing court officials to employ a singing master, two basses and six boys. Jurij Slatkonja became the director of the ensemble. The role of the choir (numbering between 24 and 26) was to provide musical accompaniment for the church mass. Additionally, the Haydn brothers were members of the St. Stephen's Cathedral choir, directed at the time by Georg Reutter II, who used this choir in his duties for the imperial court, which at the time had no boy choristers of its own. Over the centuries, the choir has worked with many composers, including Heinrich Isaac, Hofhaimer, Biber, Fux, Caldara, Gluck, Salieri, Mozart, Franz Schubert and Bruckner. In 1920, following the fall of the Austrian Empire, the Hofkapelle (court orchestra) was disbanded. However, the rector at the time, Josef Schnitt, sought a continuation of the tradition. In 1924, the Vienna Boys' Choir was officially founded, and it has evolved into a professional music group. The choir adopted the now-famous blue and white sailor suit, replacing the imperial military cadet uniform that included a dagger. The composer HK Gruber is one of the graduates of the reformed choir. Since 1948, the Palais Augarten has served as their rehearsal venue and boarding school, which goes from kindergarten level up to middle school level. In 1961, Walt Disney filmed Almost Angels, a fictional drama about (and starring) the Vienna Boys' Choir, set and filmed in the Palais Augarten. It was Disney who, for cinematographic reasons, persuaded the Austrian government to allow the boys to legally wear the Austrian national emblem on the breast of their uniform, a tradition that continues to this day.

Answer this question "Did any of the composers stay or stick with them?"
output:

Answer the question at the end by quoting:

Hooker's date of birth is a subject of debate; the years 1912, 1915, 1917, 1920, and 1923 have been suggested. Most sources give 1917, though at times Hooker stated he was born in 1920. Information in the 1920 and 1930 censuses indicates that he was born in 1912. In 2017, a series of events took place to celebrate the purported centenary of his birth.
Beginning in 1962, Hooker gained greater exposure when toured Europe in the annual American Folk Blues Festival. His "Dimples" became a successful single on the UK Singles Charts in 1964, eight years after its first US release. Hooker began to perform and record with rock musicians. One of his earliest collaborations was with British blues rock band the Groundhogs. In 1970, he recorded the joint album Hooker 'n Heat, with the American blues and boogie rock group Canned Heat, whose repertoire included adaptations of Hooker songs. It became the first of Hooker's albums to reach the Billboard charts, peaking at number 78 on the Billboard 200. Other collaboration albums soon followed, including Endless Boogie (1971) and Never Get Out of These Blues Alive (1972), which included Steve Miller, Elvin Bishop, Van Morrison, and others. Hooker appeared in the 1980 film The Blues Brothers. He performed "Boom Boom" in the role of a street musician. In 1989, he recorded the album The Healer with Carlos Santana, Bonnie Raitt, and others. The 1990s saw additional collaboration albums: Mr. Lucky (1991), Chill Out (1995), and Don't Look Back (1997) with Morrison, Santana, Los Lobos, and additional guest musicians. His re-recording of "Boom Boom" (the title track for his 1992 album) with guitarist Jimmie Vaughan became Hooker's highest charting single (number 16) in the UK. Come See About Me, a 2004 DVD, includes performances filmed between 1960 and 1994 and interviews with several of the musicians. Hooker died in his sleep on June 21, 2001, in Los Altos, California. He is interred at the Chapel of the Chimes in Oakland, California. He was survived by eight children, 19 grandchildren, and numerous great-grandchildren.

What was one of his hits in his later career?
His re-recording of "Boom Boom" (the title track for his 1992 album) with guitarist Jimmie Vaughan became Hooker's highest charting single (number 16) in the UK.