Given the following context:  In 1967 Solti was invited to become music director of the Chicago Symphony Orchestra. It was the second time he had been offered the post. The first had been in 1963 after the death of the orchestra's conductor, Fritz Reiner, who made its reputation in the previous decade. Solti told the representatives of the orchestra that his commitments at Covent Garden made it impossible to give Chicago the eight months a year they sought. He suggested giving them three and a half months a year and inviting Carlo Maria Giulini to take charge for a similar length of time. The orchestra declined to proceed on these lines. When Solti accepted the orchestra's second invitation it was agreed that Giulini should be appointed to share the conducting. Both conductors signed three-year contracts with the orchestra, effective from 1969.One of the members of the Chicago Symphony described it to Solti as "the best provincial orchestra in the world." Many players remained from its celebrated decade under Reiner, but morale was low, and the orchestra was $5m in debt. Solti concluded that it was essential to raise the orchestra's international profile. He ensured that it was engaged for many of his Decca sessions, and he and Giulini led it in a European tour in 1971, playing in ten countries. It was the first time in its 80-year history that the orchestra had played outside of North America. The orchestra received plaudits from European critics, and was welcomed home at the end of the tour with a ticker-tape parade.The orchestra's principal flute player, Donald Peck, commented that the relationship between a conductor and an orchestra is difficult to explain: "some conductors get along with some orchestras and not others. We had a good match with Solti and he with us." Peck's colleague, the violinist Victor Aitay said, "Usually conductors are relaxed at rehearsals and tense at the concerts. Solti is the reverse. He is very tense at rehearsals, which makes us concentrate, but relaxed during the performance, which is a great asset to the...  answer the following question:  In what year did the Chicago Symphony Orchestra travel to Europe?
1971