Question: Who was the English conductor and Director of Music for the British Broadcasting Corporation, who first performed Ralph Vaughan William's Symphony No. 6?

<P0-S0> John Charles Walsham Reith, 1st Baron Reith, {'1': ", '2': ", '3': ", '4': "} (20 July 1889 – 16 June 1971) was a British broadcasting executive who established the tradition of independent public service broadcasting in the United Kingdom. <P0-S1>  In 1922 he was employed by the BBC (British Broadcasting Company Ltd.) as its general manager; in 1923 he became its managing director and in 1927 he was employed as the Director-General of the British Broadcasting Corporation created under a Royal Charter. <P0-S2>  His concept of broadcasting as a way of educating the masses marked for a long time the BBC and similar organisations around the world. <SEP> <P1-S0> Sir Adrian Cedric Boult, CH ( ; 8 April 1889 – 22 February 1983) was an English conductor. <P1-S1>  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. <P1-S2>  His first prominent post was conductor of the City of Birmingham Orchestra in 1924. <P1-S3>  When the British Broadcasting Corporation appointed him director of music in 1930, he established the BBC Symphony Orchestra and became its chief conductor. <P1-S4>  The orchestra set standards of excellence that were rivalled in Britain only by the London Philharmonic Orchestra (LPO), founded two years later. <SEP> <P2-S0> Ralph Vaughan Williams's Symphony in E minor, published as Symphony No. 6, was composed in 1946–47, during and immediately after World War II. <P2-S1>  Dedicated to Michael Mullinar, it was first performed by Sir Adrian Boult and the BBC Symphony Orchestra on 21 April 1948. <P2-S2>  Within a year it had received some 100 performances, including the U.S. premiere by the Boston Symphony Orchestra under Serge Koussevitzky on 7 August 1948. <P2-S3>  Leopold Stokowski gave the first New York performances the following January with the New York Philharmonic and immediately recorded it, declaring that "this is music that will take its place with the greatest creations of the masters." <P2-S4>  However, Vaughan Williams, very nervous about this symphony, threatened several times to tear up the draft. <P2-S5>  At the same time, his programme note for the first performance took a defiantly flippant tone. <SEP> <P3-S0> A Sea Symphony is a piece for orchestra and chorus by Ralph Vaughan Williams, written between 1903 and 1909. <P3-S1>  Vaughan Williams' first and longest symphony, it was first performed at the Leeds Festival in 1910, with the composer conducting. <P3-S2>  The symphony's maturity belies the composer's relative youth when it was written (he was 30 when he first began sketching it). <P3-S3>  One of the first symphonies in which a choir is used throughout the work and is an integral part of the musical texture, "A Sea Symphony" helped set the stage for a new era of symphonic and choral music in Britain during the first half of the 20th century. <P3-S4>  The work is sometimes referred to as the Symphony No. 1.