Question: Why is the ethnomusicologist, Bela Viktor Janos Bartok's Piano Concerto No. 2 in G major considered notorious?

full_context: Document 1: Piano Concerto No. 2 (Chopin): The Piano Concerto No. 2 in F minor, Op. 21, is a piano concerto composed by Frédéric Chopin in 1829. Chopin wrote the piece before he had finished his formal education, at around 20 years of age. It was first performed on 17 March 1830, in Warsaw, Poland, with the composer as soloist. It was the second of his piano concertos to be published (after the Piano Concerto No. 1), and so was designated as "No. 2", even though it was written first.
Document 2: Balázs Kocsár: Balázs Kocsár is a Hungarian orchestral and operatic conductor. He was born in 1963 in Budapest. His father Miklós Kocsár is a composer awarded the Kossuth Prize. He studied composition at Béla Bartók Vocational School of Music (Bartók Béla Zeneművészeti Szakközépiskola). Then he entered the prestigious Franz Liszt Academy of Music to study choir conducting under István Párkai which was followed by studies in orchestral conducting under the guidance of Ervin Lukács. He graduated with distinction in 1991. His studies were continued at Universität für Musik und darstellende Kunst Wien under Professor Karl Österreicher. He also participated in master classes led by Helmuth Rilling, Jorma Panula, Moshe Atzmon and Péter Eötvös.
Document 3: Franz Liszt: Franz Liszt (] ; Hungarian: "Liszt Ferencz" , in modern usage "Liszt Ferenc", ] ; October 22, 1811July 31, 1886) was a prolific 19th-century Hungarian composer, virtuoso pianist, conductor, music teacher, arranger, organist, philanthropist, author, nationalist and a Franciscan tertiary.
Document 4: Piano Concerto No. 25 (Mozart): The Piano Concerto No. 25 in C major, K. 503, was completed by Wolfgang Amadeus Mozart on December 4, 1786, alongside the Prague Symphony, K. 504. Although two more concertos (K. 537 and K. 595) would later follow, this work is the last of what are considered the twelve great piano concertos written in Vienna between 1784 and 1786. Chronologically the work is the 21st of Mozart's 23 original piano concertos.
Document 5: Piano sonatas (Chopin): Frédéric Chopin composed three piano sonatas, two being published in his lifetime, one posthumously. They are often considered to be among Chopin's hardest piano compositions both musically (along with his Polonaise-fantaisie, Op. 61) and technically (along with his Allegro de concert, Op. 46). They cover a period of time from 1828 to 1844, reflecting Chopin's style changes.
Document 6: Life of Franz Liszt: Franz Liszt (October 22, 1811July 31, 1886) was a prolific 19th-century Hungarian composer, virtuoso pianist, conductor, music teacher, arranger, organist, philanthropist, author, nationalist and a Franciscan tertiary. Liszt is widely considered to be the greatest pianist of all time.
Document 7: Béla Bartók Music High School: Béla Bartók Music High School (Bartók Béla Zeneművészeti Szakközépiskola) is situated in the Palace of Music (Zenepalota) in Bartók square Miskolc, Hungary.It is a famous Music school named after the famous Hungarian composer Béla Bartók.It was founded in 1966.
Document 8: Piano Concerto No. 5 (Prokofiev): The last complete piano concerto by Sergei Prokofiev, Piano Concerto No. 5 in G major, Op. 55, dates from 1932.
Document 9: List of compositions by Béla Bartók: This aspires to be a complete list of compositions by Béla Bartók. The catalogue numbering by András Szőllősy (Sz.), László Somfai (BB.) and Denijs Dille (DD.) are provided, as well as Bartók's own opus numbers. Note that Bartók started three times anew with opus numbers, here indicated with "(list 1)", "(list 2)" and "(list 3)" respectively. The pieces from the third listing are by far best known; opus lists 1 and 2 are early works. The year of composition and instrumentation (including voice) are included. See the main article on Béla Bartók for more details.
Document 10: Béla Bartók: Béla Viktor János Bartók ( ; ] ; 25 March 1881 – 26 September 1945) was a Hungarian composer, pianist and an ethnomusicologist. He is considered one of the most important composers of the 20th century; he and Liszt are regarded as Hungary's greatest composers . Through his collection and analytical study of folk music, he was one of the founders of comparative musicology, which later became ethnomusicology.
Document 11: Palace of Music (Miskolc): The Palace of Music ("Zenepalota") is a building in Bartók square, Miskolc, Hungary. It is the building of the Béla Bartók Secondary School and the Béla Bartók Music Institute (a faculty of the University of Miskolc.) The Palace was designed by Gyula Waelder in Neo-baroque style and was built between 1926 and 1927. The construction was financed from USA loans, just like that of the Hotel Palace in Lillafüred and the Market Hall on Búza tér.
Document 12: List of string quartets by Béla Bartók: The Hungarian composer Béla Bartók wrote six string quartets, each for the usual forces of two violins, viola and cello. Notable composers who have been influenced by them include Benjamin Britten, particularly in the Sonata in C for Cello and Piano (; ), Elliott Carter, who refers in the opening of his own First String Quartet to Bartók’s Sixth Quartet , Chen Yi , Edison Denisov, whose Second Quartet is closely related to Bartók’s Fifth Quartet , Franco Donatoni, who was deeply impressed when he heard a broadcast of Bartók's Fourth Quartet , Robert Fripp, who mentions them as an influence upon King Crimson , Miloslav Ištvan , György Kurtág, whose Opp. 1 and 28 both owe a great deal to Bartók's quartets (; ), György Ligeti, whose two string quartets both owe a great deal to Bartók’s quartets (; ), Bruno Maderna , George Perle, who credits the Bartók Fourth and Fifth Quartets as precedents for his use of arrays of chords related to one another by different types of symmetry , Walter Piston (; ), Kim Dzmitrïyevich Tsesakow , Wilfried Westerlinck , Stefan Wolpe, who explained in a public lecture how he had derived ideas from Bartók’s Fourth Quartet , and Xu Yongsan .
Document 13: Piano Concerto No. 2 (Bartók): Béla Bartók's Piano Concerto No. 2 in G major, Sz. 95, BB 101 (1930–31) is the second of three piano concerti, and is notorious for being one of the most difficult pieces in the repertoire.
Document 14: Piano Concerto No. 2 (Prokofiev): Sergei Prokofiev set to work on his Piano Concerto No. 2 in G minor, Op. 16, in 1912 and completed it in 1913. But this concerto is lost; the score was destroyed in a fire following the Russian Revolution. Prokofiev reconstructed the work in 1923, two years after finishing his Third Concerto, and declared it to be “so completely rewritten that it might almost be considered [Concerto] No. 4”; indeed its orchestration has features that clearly postdate the 1921 concerto. Performing as solo pianist, Prokofiev premiered this surviving “No. 2” in Paris on 8 May 1924 with Serge Koussevitzky conducting. It is dedicated to the memory of Maximilian Schmidthof, a friend of Prokofiev's at the St. Petersburg Conservatory who had killed himself in 1913.
Document 15: Balázs Fülei: Balázs Fülei was born in Kecskemét, Hungary 1984. He started to learn music at the age of eight, his first teacher was Katonáné Szabó Judit. In the Bartók Conservatory, Budapest, his professors were Gábor Eckhardt and Balázs Réti, then he made his diploma with honours at the Franz Liszt Academy of Music, Budapest, 2008 in György Nádor, Márta Gulyás and Balázs Réti’s class. Balázs Fülei was an active participant in prof. Amadeus Webersinke, Florent Boffard, Ferenc Rados, Gábor Csalog, Norma Fischer, Zoltán Kocsis, Bertrand Ott, Jan Marisse Huizing, Jan Wijn, Boris Berman and György Kurtág's piano and chamber music courses. Balázs Fülei is living an active musical life as a concert pianist, he gave several concerts almost in every country in Europe, in China, Japan, Australia and in the United States. He was an artist of the International Miami Piano Festival, and the Ferruccio Busoni Festival. He won the 1st prize on the 10th Hungarian National Piano Competition, and in the Andor Földes Piano Competition of Liszt Academy of Music in 2003. He was the winner of the 43. "Arcangelo Speranza" International Piano Competition in Taranto Italy, May 2005, 3rd prize winner of the 25. International Piano Competition „Ettore Pozzoli” in Milan-Seregno in 2007. In 2007 Balázs Fülei got a special prize in the 13. International Tchaikovsky Competition in Moscow. He was selected twice to the New Masters On Tour by The International Holland Music Sessions in The Netherlands and played in 2007 in the Concertgebouw, Diligentia Den Haag and other capitals in Europe. He performed in a DVD recording in May 2006 in Tokyo, Japan with the ballades of Chopin and Liszt, then made his New York debut in Carnegie Hall, 2008. Balázs Fülei plays chamber and contemporary music many times, he played world prémieres of Hungarian composers. He is an artist of the Starlet Music Management.
ground_truth: is notorious for being one of the most difficult pieces in the repertoire.