In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.

Passage: In 1971, Bob Shad, who had worked with her as producer at Mercury, asked her to record for his label, Mainstream, which he had founded after leaving Mercury. Breaking a four-year hiatus, Vaughan signed a contract with Mainstream and returned to the studio for A Time in My Life, a step away from jazz into pop music with songs by Bob Dylan, John Lennon, and Marvin Gaye arranged by Ernie Wilkins. She didn't complain about this eclectic change in direction, but she chose the material for her next album after admiring the work of Michel Legrand. He conducted an orchestra of over one hundred musicians for Sarah Vaughan with Michel Legrand, an album of compositions by Legrand with lyrics by Alan and Marilyn Bergman. The songs brought some of the musicians to tears during the sessions. But Shad wanted a hit, and the album yielded none. She sang a version of the pop hit "Rainy Days and Mondays" by the Carpenters for Feelin' Good. This was followed by Live in Japan, her first live album since 1963. Sarah Vaughan and the Jimmy Rowles Quintet (1974) was more experimental, containing free improvisation and some unconventional scatting.
 Link Information: Mainstream Records was an American record company and independent record label founded by music producer Bob Shad in 1964. Answer: 1964
What year did Vaughn's producer form hiw own label after leaving Mercury?

Passage: In modern times, the creation of relatively simple dome-like structures has been documented among various indigenous peoples around the world. The wigwam was made by Native Americans using arched branches or poles covered with grass or hides. The Efé people of central Africa construct similar structures, using leaves as shingles. Another example is the igloo, a shelter built from blocks of compact snow and used by the Inuit people, among others. The Himba people of Namibia construct "desert igloos" of wattle and daub for use as temporary shelters at seasonal cattle camps, and as permanent homes by the poor. Extraordinarily thin domes of sun-baked clay 20 feet in diameter, 30 feet high, and nearly parabolic in curve, are known from Cameroon.
 Link Information: It is rather difficult to accurately describe the Efé religion, as there is not a great deal of information that deals specifically with the Efé. Answer: It is rather difficult to accurately describe the Efé religion, as there is not a great deal of information that deals specifically with the Efé.
What religion did the Efe people follow?

Passage: In 1938 Rudenko was signed up to the Ballet Russe de Monte Carlo, where, at 17, she was their youngest soloist. Her stage name was Lubov Roudenko, and she was also popularly known as "Spitfire Lu-Lu." She had a can-can sequence in the 1938 ballet Gaîté Parisienne choreographed specially for her by Léonide Massine. She would later reprise this role in the 1941 Oscar-nominated short film The Gay Parisian. Whilst with the Ballet Russes, Rudenko was the subject of several drawings by Henri Matisse in 1939. Four of his portrait sketches of her are now in the Fogg Museum. Matisse also made a drawing of Rudenko in the ballet  Rouge et Noir. While on tour with the Ballet Russe, Rudenko performed the role of the Cowgirl in the 1942 ballet Rodeo until the tour reached New York and Agnes de Mille, the original choreographer, reclaimed the role for herself. Disappointed by this, Rudenko quit the Ballet Russes, and took a better-paid job performing in a Broadway production of The Merry Widow. This production launched at the Majestic Theatre on 4 August 1943, with Rudenko and James Starbuck leading the character dances, including a comic polka and a can-can number. After this, Rudenko played Grisette in Nellie Bly, a short-lived 1946 musical based on the life of Nellie Bly, and then became lead dancer for the 1946-49 Broadway production of Annie Get Your Gun, but following a knee injury, decided to pursue a career in fashion design. She continued performing until 1951, appearing in the 1950-51 Olsen and Johnson revue Pardon our French.
 Link Information: The company Ballets Russes de Monte-Carlo (note the plural) was formed in 1932  Answer: 6

How many years had the Ballet Russe de Monte Carlo been doing performances the year that Rudenko signed up with them?