Today foreign stars coming to Russia is absolutely normal. But it used to be a whole event in the Soviet times. Some of them came for performing or as tourists, others were invited to take part in festivals.
David Bowie was travelling by train "Vladivostok-Moscow" in 1973. He refused to fly by plane due to his phobia. Later he wrote that he was buying various food from grannies at the stations, allegedly it didn't look yummy but turned out to be very delicious.
He was rather impressed by Siberia, its vast territories and girls - conductors who were treating him to tasty tea. He even sang songs to them at nights.