While Michał Zieliński was in Truskawiec-Zdrój, he made the best composition of his life, a song entitled "Serce w plecaku". The beginning was very simple… In 1933 anewspaper "Żołnierz Polski" announced a competitionfor a poem which Michał Zieliński took partin. Firstly, hiswinning entry was shown in the press then in a collection of poems "Wiersze Żołnierskie". It’s worth adding that Michał Zieliński is the author of both the lyrics and the melody of his song. However, Zieliński should be remembered not only as the author of one song. He made a lot of wonderful compositions: songs, poems and even a musical comedy "Partyzanci w niebie".