Question: Which English conductor worked for both the Halle Orchestra and Sergie Diaghilev's ballet company?
Context: The Manitoba Chamber Orchestra was founded in 1972 by Ruben Gurevich.  Gurevich served as music director and principal conductor until 1981.  After a season of guest conductors, English conductor Simon Streatfeild, a founding member of the prestigious London-based chamber orchestra, the Academy of St. Martin in the Fields, was appointed music director and principal conductor in 1982.  He was succeeded by another English conductor, Roy Goodman (2000-2005), and then by Anne Manson, who began her tenure in 2008. English National Ballet is a classical ballet company founded by Dame Alicia Markova and Sir Anton Dolin and based at Markova House in South Kensington, London, England.  Along with The Royal Ballet, Birmingham Royal Ballet and Scottish Ballet, it is one of the four major ballet companies in Great Britain.  English National Ballet is one of the foremost touring companies in Europe, performing in theatres throughout the UK as well as conducting international tours and performing at special events.  The Company employs approximately 67 dancers and a symphony orchestra, (English National Ballet Philharmonic) and there is also an associate school, English National Ballet School, which is independent from the ballet company.  The Company regularly performs seasons at the London Coliseum and has been noted for specially staged performances at the Royal Albert Hall.  In 2014 English National Ballet became an Associate Company of Sadler's Wells.  The Patron of English National Ballet is HRH The Duke of York. Ballet Master (also "Balletmaster", "Ballet Mistress" [increasingly archaic English language use], "Premier Maître de ballet" or "Premier Maître de ballet en Chef") is the term used for an employee of a ballet company who is responsible for the level of competence of the dancers in their company.  In modern times, ballet masters are generally charged with teaching the daily company ballet class and rehearsing the dancers for both new and established ballets in the company's repertoire.  The artistic director of a ballet company, whether a male or female, may also be called its ballet master.  Historic use of gender marking in job titles in ballet (and live theatre) is being supplanted by gender-neutral language job titles regardless of an employee's gender identity or expression (e.g. "Ballet Master" in lieu of "Ballet Mistress", "Wig Master" as an alternative to "Wig Mistress"). Sir Adrian Cedric Boult, CH ( ; 8 April 1889 – 22 February 1983) was an English conductor.  Brought up in a prosperous mercantile family, he followed musical studies in England and at Leipzig, Germany, with early conducting work in London for the Royal Opera House and Sergei Diaghilev's ballet company.  His first prominent post was conductor of the City of Birmingham Orchestra in 1924.  When the British Broadcasting Corporation appointed him director of music in 1930, he established the BBC Symphony Orchestra and became its chief conductor.  The orchestra set standards of excellence that were rivalled in Britain only by the London Philharmonic Orchestra (LPO), founded two years later. Colin Sauer (13 July 1924 - 9 January 2015 ) was a violinist and chamber musician who lead the Dartington String Quartet for over 20 years.  He played with the Hallé Orchestra under John Barbirolli and the BBC Symphony Orchestra under Adrian Boult. The Sheffield Philharmonic Orchestra is an amateur symphony orchestra based in Sheffield, England.  Formed in 1945, it performs a programme of music from the classical, romantic and modern periods.  The orchestra is in a phase of development, initially under the baton of John Pearson followed by the Polish born Ewa Strusinska (assistant conductor of the Halle orchestra, 2009-2011).  In 2010, the music directorship passed on to Jonathan Lo, a graduate of the Royal Northern College of Music.  The regular programme of symphony concerts is supplemented by music weekends, foreign tours, collaboration with local choral societies and open air charity concerts.  The orchestra has established collaborative ties with music groups and musicians in Malta, Greece and Northern Sardinia.  In the past, the orchestra has worked with the acoustic guitar player Gordon Giltrap and has commissioned a major new work from the English composer Christopher Brown. Dame Alicia Markova DBE (1 December 1910 – 2 December 2004) was an English ballerina and a choreographer, director and teacher of classical ballet.  Most noted for her career with Sergei Diaghilev's Ballets Russes and touring internationally, she was widely considered to be one of the greatest classical ballet dancers of the twentieth century.  She was the first British dancer to become the principal dancer of a ballet company and, with Dame Margot Fonteyn, is one of only two English dancers to be recognised as a prima ballerina assoluta.  Markova was a founder dancer of the Rambert Dance Company, The Royal Ballet and American Ballet Theatre, and was co-founder and director of the English National Ballet. Dudley Bright has been Principal Trombone for the London Symphony Orchestra since 2000, and is also Professor of Trombone at the Royal Academy of Music.  Before that he was for many years in the same position at the Philharmonia Orchestra and Halle Orchestra and before that briefly as an associate with the LSO. Helen Vollam (born June 7, 1974) is Principal Trombone for the BBC Symphony Orchestra.  In 2004, she was the first woman to be appointed principal trombone in a London orchestra, and the first in a UK orchestra since Maisie Ringham of the Halle Orchestra in the last century.  She joined the trombone quartet, Bones Apart, in 2007, and is also an Associate member of the Chamber Orchestra of Europe. The Original Ballet Russe (originally named Les Ballets Russes de Monte Carlo) was a ballet company established in 1931 by René Blum and Colonel Wassily de Basil as a successor to the "Ballets Russes", founded in 1909 by Sergei Diaghilev.  The company assumed the new name "Original Ballet Russe" after a split between de Basil and Blum.  De Basil led the renamed company, while Blum and others founded a new company under the name "Ballet Russe de Monte Carlo".  It was a large scale professional ballet company which toured extensively in Europe, Australia and New Zealand, the United States, and Central and South America.  It closed down operations in 1947.
Answer: Adrian Boult