Composer and committed community activist. In 1926 he was one of the founders of the Association of Young Polish Musicians in Paris. In 1945 he became the first President of the Polish Composers’ Union. Mycielski met him shortly after arriving in Paris to study and with time became friends with him. After the war the two men worked together in the Polish Composers’ Union. Reminiscing years later about his work in the Association of Young Polish Musicians and his arrival in Poland after being liberated from German captivity, Mycielski wrote:

So I came to Warsaw in 1945. There was no place to stay, a plank bed in some Red Cross barracks again, some straw again, I had enough. Someone told me that there was some association of musicians somewhere. Finally, I found out where it was – in Wilcza [Złota – B.B-L.] Street, shabby stairs, no windows, I dragged myself there and what do I see: several of my colleagues sitting there, Perkowski of course presiding, he sees me and says as if nothing happened [...]: ‘ah, you’re alive, you’re back. Sit down. What do you need?’ I sat down and no more was said of my five-year absence (Zygmunt Mycielski, in "Wspomnienia i refleksje”, Muzyka 1978 no. 3).