Information:  - The Society for Private Musical Performances (in German, the Verein für musikalische Privataufführungen) was an organization founded in Vienna in the Autumn of 1918 by Arnold Schoenberg with the intention of making carefully rehearsed and comprehensible performances of newly composed music available to genuinely interested members of the musical public. In the three years between February 1919 and 5 December 1921 (when the "Verein" had to cease its activities due to Austrian hyperinflation), the organisation gave 353 performances of 154 works in a total of 117 concerts.  - Arnold Schoenberg or Schönberg (13 September 187413 July 1951) was an Austrian composer, music theorist, and painter. He was associated with the expressionist movement in German poetry and art, and leader of the Second Viennese School. By 1938, with the rise of the Nazi Party, Schoenberg's works were labeled degenerate music, because he was Jewish . He moved to the United States in 1934.  - Centrope is an Interreg IIIA project to establish a multinational region in the Central Europe encompassing four European countries: Slovakia, Austria, Hungary and Czech Republic.  - Berlin is the capital and the largest city of Germany as well as one of its constituent 16 states. With a population of approximately 3.5 million people, Berlin is the second most populous city proper and the seventh most populous urban area in the European Union. Located in northeastern Germany on the banks of rivers Spree and Havel, it is the centre of the Berlin-Brandenburg Metropolitan Region, which has about 6 million residents from more than 180 nations. Due to its location in the European Plain, Berlin is influenced by a temperate seasonal climate. Around one-third of the city's area is composed of forests, parks, gardens, rivers and lakes.  - For the former German football player , see Erwin Stein . Erwin Stein ( 7 November 1885 -- 17 July 1958 ) was an Austrian musician and writer , prominent as a pupil and friend of Schoenberg , with whom he studied between 1906 and 1910 . He was one of Schoenberg 's principal assistants in organizing the Society for Private Musical Performances . In 1924 it was Stein to whom Schoenberg entrusted the delicate as well as important task of writing the first article -- Neue Formprinzipien ( ' New Formal Principles ' ) -- on the gradual evolution of what was soon to be explicitly formulated as ' twelve tone technique ' . Until 1938 he lived in Vienna , where he was respected as a music teacher and conductor as well as a writer active on behalf of the music and composers he valued . After the Anschluss he fled to London to escape the Nazis and worked for many years as an editor for the music publishers Boosey & Hawkes . His focus was mainly on Mahler , Schoenberg and Britten ( all three of whom he knew personally ) as well as his colleagues within the Schoenberg circle , Berg and Webern . His books include Orpheus in New Guises ( a collection of writings from the period 1924 -- 1953 ) and Form and Performance ( 1962 ) . He was the editor of the first collection of Schoenberg 's letters ( Germany 1958 ; UK 1964 ) . He was also instrumental in setting up the modern music periodical Tempo in 1939 . Stein married Sophie Bachmann ( 1883 ? -- 1965 ) , and their daughter , the pianist Marion Stein , married successively George Lascelles , 7th Earl of Harewood and the Liberal politician Jeremy Thorpe .  - The European Union (EU) is a political and economic union of member states that are located primarily in Europe. It has an area of , and an estimated population of over 510 million. The EU has developed an internal single market through a standardised system of laws that apply in all member states. EU policies aim to ensure the free movement of people, goods, services, and capital within the internal market, enact legislation in justice and home affairs, and maintain common policies on trade, agriculture, fisheries, and regional development. Within the Schengen Area, passport controls have been abolished. A monetary union was established in 1999 and came into full force in 2002, and is composed of 19 EU member states which use the euro currency.  - Bratislava (or  also known by ) is the capital of Slovakia, and with a population of about 450,000, the country's largest city. The greater metropolitan area is home to more than 650,000 people. Bratislava is in southwestern Slovakia, occupying both banks of the River Danube and the left bank of the River Morava. Bordering Austria and Hungary, it is the only national capital that borders two sovereign states.  - Organization of the Petroleum Exporting Countries (OPEC, , or OPEP in several other languages) is an intergovernmental organization of 13 nations, founded in 1960 in Baghdad by the first five members (Iran, Iraq, Kuwait, Saudi Arabia, Venezuela), and headquartered since 1965 in Vienna. As of 2015, the 13 countries accounted for an estimated 42 percent of global oil production and 73 percent of the world's "proven" oil reserves, giving OPEC a major influence on global oil prices that were previously determined by American-dominated multinational oil companies.  - World War I (WWI or WW1), also known as the First World War, or the Great War, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. More than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history. Over nine million combatants and seven million civilians died as a result of the war (including the victims of a number of genocides), a casualty rate exacerbated by the belligerents' technological and industrial sophistication, and the tactical stalemate caused by gruelling trench warfare. It was one of the deadliest conflicts in history, and paved the way for major political changes, including revolutions in many of the nations involved.  - Vienna is the capital and largest city of Austria and one of the nine states of Austria. Vienna is Austria's primary city, with a population of about 1.8 million (2.6 million within the metropolitan area, nearly one third of Austria's population), and its cultural, economic, and political centre. It is the 7th-largest city by population within city limits in the European Union. Until the beginning of the 20th century, it was the largest German-speaking city in the world, and before the splitting of the Austro-Hungarian Empire in World War I, the city had 2 million inhabitants. Today, it has the second largest number of German speakers after Berlin. Vienna is host to many major international organizations, including the United Nations and OPEC. The city is located in the eastern part of Austria and is close to the borders of the Czech Republic, Slovakia, and Hungary. These regions work together in a European Centrope border region. Along with nearby Bratislava, Vienna forms a metropolitan region with 3 million inhabitants. In 2001, the city centre was designated a UNESCO World Heritage Site.  - The United Nations (UN) is an intergovernmental organization to promote international co-operation. A replacement for the ineffective League of Nations, the organization was established on 24 October 1945 after World War II in order to prevent another such conflict. At its founding, the UN had 51 member states; there are now 193. The headquarters of the United Nations is in Manhattan, New York City, and experiences extraterritoriality. Further main offices are situated in Geneva, Nairobi, and Vienna. The organization is financed by assessed and voluntary contributions from its member states. Its objectives include maintaining international peace and security, promoting human rights, fostering social and economic development, protecting the environment, and providing humanitarian aid in cases of famine, natural disaster, and armed conflict.  - The Czech Republic, also known by the short name Czechia, is a nation state in Central Europe bordered by Germany to the west, Austria to the south, Slovakia to the east and Poland to the northeast. The Czech Republic covers an area of with mostly temperate continental climate and oceanic climate. It is a unitary parliamentary republic, has 10.5 million inhabitants and the capital and largest city is Prague, with over 1.2 million residents. The Czech Republic includes the historical territories of Bohemia, Moravia, and Czech Silesia.  - Slovakia, officially the Slovak Republic, is a landlocked country in Central Europe. It is bordered by the Czech Republic and Austria to the west, Poland to the north, Ukraine to the east and Hungary to the south. Slovakia's territory spans about and is mostly mountainous. The population is over 5 million and comprises mostly ethnic Slovaks. The capital and largest city is Bratislava. The official language is Slovak, a member of the Slavic language family.  - Hungary is a unitary parliamentary republic in Central Europe. It covers an area of , situated in the Carpathian Basin and bordered by Slovakia to the north, Romania to the east, Serbia to the south, Croatia to the southwest, Slovenia to the west, Austria to the northwest, and Ukraine to the northeast. With about 10 million inhabitants, Hungary is a medium-sized member state of the European Union. The official language is Hungarian, which is the most widely spoken Uralic language in the world. Hungary's capital and largest metropolis is Budapest, a significant economic hub, classified as an Alpha- global city. Major urban areas include Debrecen, Szeged, Miskolc, Pécs and Gyr.    What entity does 'erwin stein' has the relation 'member of' with?
The answer to this question is:
second viennese school