He was an advisor to singer Udo Lindenberg. Since the 1970s, Lindenberg had wanted to perform in the GDR, but with the release of the song Sonderzug nach Pankow in early 1983, his chances of performing in the GDR had been greatly reduced. Therefore, on August 23, 1983, Gaißmayer wrote a letter on behalf of Lindenberg to Erich Honecker. Thus, Gaißmayer initiated Udo Lindenberg's first appearance in the GDR. Honecker read the letter favorably and gave it to Krenz with the order to organize Lindenberg's appearance. Krenz obtained Honecker's final approval for the appearance in a letter dated September 8, 1983. The appearance then took place on October 25, 1983 in the Palace of the Republic as part of the event For World Peace. Gaißmayer's girlfriend at the time, the Swedish photographer Kristina Eriksson, who had already typed the letter to Honecker on the typewriter in the West Berlin Hotel Intercontinental, took pictures of Krenz and Lindenberg at the concert, as no West German media were allowed in the palace that day.
