Armstrong continued his heavy schedule of touring and recording through the 1950s. He became an unofficial ambassador for jazz by visiting such unlikely destinations as the Soviet Union, Japan, and parts of Africa, proof that his artistry and charm transcended all borders. There were memorable collaborations with Duke Ellington, Bing Crosby, Ella Fitzgerald, and the Oscar Peterson Trio and several albums from this period like Satch Plays Fats and Ella and Louis were top sellers. Not even a heart attack could slow him down in 1959, as he was back on the road in a matter of weeks. The king of trumpet playing always put his art first.