Question: In 1939, what was signed by the Soviet Union and the country where the person who played Yellow Fields is a citizen?

full_context: Document 1: Chorus (Eberhard Weber album): Chorus is an album by German double bassist and composer Eberhard Weber featuring Jan Garbarek and Ralf-R. Hübner recorded in 1984 and released on the ECM label.
Document 2: Silent Feet: Silent Feet is an album by German double bassist and composer Eberhard Weber recorded in 1977 and released on the ECM label.
Document 3: Germany–Soviet Union relations, 1918–1941: Cooperation ended in 1933, as Adolf Hitler came to power and created Nazi Germany. The countries' economic relationship dwindled at the beginning of the Nazi era, but some diplomatic initiatives continued through the 1930s, culminating with the Molotov -- Ribbentrop Pact of 1939 and various trade agreements. Few questions concerning the origins of the Second World War are more controversial and ideologically loaded than the issue of the policies of the Soviet Union under Joseph Stalin towards Nazi Germany between the Nazi seizure of power and the German invasion of the USSR on June 22, 1941.
Document 4: Eberhard Weber: Eberhard Weber (born 22 January 1940 in Stuttgart) is a German double bassist and composer. As a bass player, he is known for his highly distinctive tone and phrasing. Weber's compositions blend chamber jazz, European classical music, minimalism and ambient music, and are regarded as characteristic examples of the ECM Records sound.
Document 5: Later That Evening: Later That Evening is an album by German double bassist and composer Eberhard Weber recorded in 1982 and released on the ECM label.
Document 6: Résumé (Eberhard Weber album): Résumé is a live album by German double bassist and composer Eberhard Weber recorded at various locations between 1990 and 2007 and released on the ECM label.
Document 7: Molotov–Ribbentrop Pact: The Molotov -- Ribbentrop Pact, also known as the Nazi -- Soviet Pact, the German -- Soviet Non-aggression Pact or the Nazi German -- Soviet Pact of Aggression (officially: Treaty of Non-aggression between Germany and the Union of Soviet Socialist Republics), was a neutrality pact between Nazi Germany and the Soviet Union signed in Moscow on 23 August 1939 by foreign ministers Joachim von Ribbentrop and Vyacheslav Molotov, respectively. The pact was followed by the German - Soviet Commercial Agreement in February 1940.
Document 8: History of Germany: In the early 1930s, the worldwide Great Depression hit Germany hard, as unemployment soared and people lost confidence in the government. In January 1933, Adolf Hitler was appointed Chancellor of Germany. His Nazi Party quickly established a totalitarian regime, and Nazi Germany made increasingly aggressive territorial demands, threatening war if they were not met. Remilitarization of the Rhineland came in 1936, then annexation of Austria in the Anschluss and parts of Czechoslovakia with the Munich Agreement in 1938, and further territory of Czechoslovakia in 1939. On 1 September 1939, Germany initiated World War II in Europe with the invasion of Poland. After forming a pact with the Soviet Union in 1939, Hitler and Stalin divided Eastern Europe. After a "Phoney War" in spring 1940, the Germans swept Denmark and Norway, the Low Countries, and France, giving Germany control of nearly all of Western Europe. Hitler invaded the Soviet Union in June 1941.
Document 9: Stages of a Long Journey: Stages of a Long Journey is a live album by German double bassist and composer Eberhard Weber recorded in Germany in 2005 and released on the ECM label.
Document 10: Molotov–Ribbentrop Pact: The Molotov -- Ribbentrop Pact, also known as the Nazi -- Soviet Pact, the German -- Soviet Non-aggression Pact or the Nazi German - Soviet Pact of Aggression (officially: Treaty of Non-aggression between Germany and the Union of Soviet Socialist Republics), was a neutrality pact between Nazi Germany and the Soviet Union signed in Moscow on 23 August 1939 by foreign ministers Joachim von Ribbentrop and Vyacheslav Molotov, respectively. The pact was followed by the German - Soviet Commercial Agreement in February 1940.
Document 11: The Following Morning: The Following Morning is an album by German double bassist and composer Eberhard Weber recorded in 1976 and released on the ECM label.
Document 12: Yellow Fields: Yellow Fields is an album by German double bassist and composer Eberhard Weber recorded in 1975 and released on the ECM label.
Document 13: Little Movements: Little Movements is an album by German double bassist and composer Eberhard Weber recorded in 1980 and released on the ECM label.
Document 14: Molotov–Ribbentrop Pact: At the beginning of the 1930s, the Nazi Party's rise to power increased tensions between Germany and the Soviet Union along with other countries with ethnic Slavs, who were considered "Untermenschen" (inferior) according to Nazi racial ideology. Moreover, the anti-Semitic Nazis associated ethnic Jews with both communism and financial capitalism, both of which they opposed. Consequently, Nazi theory held that Slavs in the Soviet Union were being ruled by "Jewish Bolshevik" masters. In 1934, Hitler himself had spoken of an inescapable battle against both Pan-Slavism and Neo-Slavism, the victory in which would lead to "permanent mastery of the world", though he stated that they would "walk part of the road with the Russians, if that will help us." The resulting manifestation of German anti-Bolshevism and an increase in Soviet foreign debts caused German–Soviet trade to dramatically decline.[b] Imports of Soviet goods to Germany fell to 223 million Reichsmarks in 1934 as the more isolationist Stalinist regime asserted power and the abandonment of post–World War I Treaty of Versailles military controls decreased Germany's reliance on Soviet imports.[clarification needed]
Document 15: The Colours of Chloë: The Colours of Chloë is an album by German double bassist and composer Eberhard Weber recorded in 1973 and released on the ECM label.
ground_truth: Molotov -- Ribbentrop Pact of 1939
sub_queries: Who sang or played Yellow Fields? Answer: Eberhard Weber
Eberhard Weber >> country of citizenship Answer: Germany
what did Germany and the soviet union sign in 1939 Answer: Molotov -- Ribbentrop Pact of 1939