Article: Stereophonic sound recording, which attempts to provide a more natural listening experience by reproducing the spatial locations of sound sources in the horizontal plane, was the natural extension to monophonic recording, and attracted various alternative engineering attempts. The ultimately dominant "45/45" stereophonic record system was invented by Alan Blumlein of EMI in 1931 and patented the same year. EMI cut the first stereo test discs using the system in 1933 (see Bell Labs Stereo Experiments of 1933) although the system was not exploited commercially until much later.

Question: What year was stereo sound patented? 
Ans: 1931


Article: Tito's estrangement from the USSR enabled Yugoslavia to obtain US aid via the Economic Cooperation Administration (ECA), the same US aid institution which administered the Marshall Plan. Still, he did not agree to align with the West, which was a common consequence of accepting American aid at the time. After Stalin's death in 1953, relations with the USSR were relaxed and he began to receive aid as well from the COMECON. In this way, Tito played East-West antagonism to his advantage. Instead of choosing sides, he was instrumental in kick-starting the Non-Aligned Movement, which would function as a 'third way' for countries interested in staying outside of the East-West divide.

Question: What plan was also administered by the ECA?
Ans: Marshall Plan


Article: In 1836, at a party hosted by Marie d'Agoult, Chopin met the French author George Sand (born [Amantine] Aurore [Lucile] Dupin). Short (under five feet, or 152 cm), dark, big-eyed and a cigar smoker, she initially repelled Chopin, who remarked, "What an unattractive person la Sand is. Is she really a woman?" However, by early 1837 Maria Wodzińska's mother had made it clear to Chopin in correspondence that a marriage with her daughter was unlikely to proceed. It is thought that she was influenced by his poor health and possibly also by rumours about his associations with women such as d'Agoult and Sand. Chopin finally placed the letters from Maria and her mother in a package on which he wrote, in Polish, "My tragedy". Sand, in a letter to Grzymała of June 1838, admitted strong feelings for the composer and debated whether to abandon a current affair in order to begin a relationship with Chopin; she asked Grzymała to assess Chopin's relationship with Maria Wodzińska, without realising that the affair, at least from Maria's side, was over.

Question: What did Chopin write on the package that contained letters from Maria and her mother?
Ans: My tragedy


Article: In addition to these popular examples of house, there has also been a reunification of contemporary house and its roots. Many hip hop and R&B artists also turn to house music to add a mass appeal to the music they produce.

Question: What genre of artists has recently turned to house music to add mass appeal?
Ans:
hip hop and R&B