Question: What was the writer of Symphony in B minor a spokesperson for?

Context articles: Gloria in excelsis Deo, BWV 191
Metamorphosis-Symphonies
Symphony in B minor (Paderewski)
Overture in the French style, BWV 831
Symphony No. 6 (Tchaikovsky)
Ignacy Jan Paderewski
Étude Op. 25, No. 10 (Chopin)
Symphony No. 7 (Mahler)
Symphony No. 1 (Furtwängler)
William Henry Reed

Gloria in excelsis Deo (Glory to God in the Highest), BWV 191 , is a church cantata written by the German Baroque composer Johann Sebastian Bach, and the only one of his church cantatas set to a Latin text.
 He composed the Christmas cantata in Leipzig probably in 1745 to celebrate the end of the Second Silesian War on Christmas Day.
 The composition's three movements all derive from the Gloria of an earlier Missa (Kyrie and Gloria in B minor) written by Bach in 1733 for the Dresden court, which the composer would later use as the Gloria of his Mass in B minor.
Metamorphosis Symphonies is the collective name for three symphonies by German composer, Martin Scherber.
 The first was composed before the outbreak of World War II in Nuremberg.
 After the war Scherber continued his musical path with the Second Symphony in F minor and the Third Symphony in B minor, which followed this directly.
The Symphony in B minor "Polonia", Op. 24, was written by Ignacy Jan Paderewski between 1903 and 1908, and first publicly performed in 1909.
 Although he lived for another 32 years, the symphony was virtually Paderewski's last composition; he wrote only one more work before his death in 1941 - a hymn for male chorus in 1917.
 Around 1910, he commenced what would become a political career, culminating in becoming the first Prime Minister of independent Poland and signing the Treaty of Versailles on behalf of his nation in 1919.
 He later returned to the concert platform as a virtuoso pianist.
The Overture in the French style, BWV 831, original title Ouvertüre nach Französischer Art, also known as the French Overture and published as the second half of Clavier-Übung II in 1735 (paired with the "Italian Concerto"), is a suite in B minor for two-manual harpsichord written by Johann Sebastian Bach.
 An earlier version of this work exists, in the key of C minor (BWV 831a); the work was transposed into B minor to complete the cycle of tonalities in Parts One and Two of the Clavier-Übung.
 The keys of the six Partitas (B♭ major, C minor, A minor, D major, G major, E minor) form a sequence of intervals going up and then down by increasing amounts: a second up (B♭ to C), a third down (C to A), a fourth up (A to D), a fifth down (D to G), and finally a sixth up (G to E).
 The key sequence continues into "Clavier-Übung II" (1735) with two larger works: the Italian Concerto, a seventh down (E to F), and the French Overture, an augmented fourth up (F to B♮ ).
 Thus this sequence of customary tonalities for 18th-century keyboard compositions is complete, extending from the first letter of his name (Bach's "home" key, B♭ , in German is B) to the last letter of his name (B♮ in German is H).
The Symphony No. 6 in B minor, Op. 74, Pathétique is Pyotr Ilyich Tchaikovsky's final completed symphony, written between February and the end of August 1893.
 The composer entitled the work "The Passionate Symphony", employing a Russian word, Патетическая ("Pateticheskaya"), meaning "passionate" or "emotional", that was then mistranslated into French as "pathétique", "evoking pity", yet the mistranslation survived subsequent productions in every country but Russia.
 The composer led the first performance in Saint Petersburg on 16/28 October of that year, nine days before his death.
 The second performance, conducted by Eduard Nápravník, took place 21 days later, at a memorial concert on 6/18 November.
 It included some minor corrections that Tchaikovsky had made after the premiere, and was thus the first performance of the work in the exact form in which it is known today.
 The first performance in Moscow was on 4/16 December, conducted by Vasily Safonov.
 It was the last of Tchaikovsky's compositions premiered in his lifetime; his last composition of all, the single-movement 3rd Piano Concerto, Op. 75, which was completed in October 1893, a short time before his death, received a posthumous premiere.
Ignacy Jan Paderewski, GBE (] ; 18 November [O.S. 6 November] 1860  – 29 June 1941) was a Polish pianist and composer, politician and spokesman for Polish independence.
 He was a favorite of concert audiences around the world.
 His musical fame opened access to diplomacy and the media.
Étude Op. 25, No. 10, in B minor is a solo piano study in B minor, composed by Frédéric Chopin in 1835.
Symphony No. 7 by Gustav Mahler was written in 1904–05, with repeated revisions to the scoring.
 It is sometimes referred to by the title Song of the Night (German: "Lied der Nacht" ), which Mahler never knew (and certainly would be unlikely to have sanctioned).
 Although the symphony is often described as being in the key of E minor, its tonal scheme is more complicated.
 The symphony's first movement moves from B minor (introduction) to E minor, and the work ends with a rondo finale in C major.
 Thus, as Dika Newlin has pointed out, "in this symphony Mahler returns to the ideal of 'progressive tonality' which he had abandoned in the Sixth".
 The complexity of the work's tonal scheme was analysed in terms of "interlocking structures" by Graham George.
Wilhelm Furtwängler's Symphony No. 1 in B minor, written between 1938 and 1941, is based on an earlier piece he wrote, a Largo in B minor from 1908.
 To this he added three more movements for a 4-movement work:
William Henry "Billy" Reed (29 July 18752 July 1942) was an English violinist, teacher, minor composer, conductor and biographer of Sir Edward Elgar.
 He was leader of the London Symphony Orchestra for 23 years (1912–1935), but is best known for his long personal friendship with Elgar (1910–1934) and his book "Elgar As I Knew Him" (1936), in which he goes into great detail about the genesis of the Violin Concerto in B minor.
 The book also provides a large number of Elgar's sketches for his unfinished Third Symphony, which proved invaluable sixty years later when Anthony Payne elaborated and essentially completed the work, although Reed wrote that in his view the symphony could not be completed.