[2] In the autumn of 1950, Trzaskowski was detained by the Polish Ministry of Public Security and imprisoned for 3 months, suspected of belonging to the underground group Pomorska.

Despite having passed his final exams cum laude, he was not admitted to Jagiellonian University due to "serious conflicts with the authorities" and was advised to wait one year before reapplying.

In parallel, he learned new composing techniques and music analysis with Bogusław Schaeffer and Eugeniusz Rudnik at the Polish Radio Experimental Studio.

In 1959, Trzaskowski moved permanently to Warsaw, when he soon established his own band, The Wreckers, also composed of Alojzy Musiał, Wojciech Karolak, Roman Dyląg and Andrzej Dąbrowski.

[2] The band drew inspiration from the music of Charlie Parker, Dizzy Gillespie, and hard bop, while Trzaskowski modelled on Horace Silver's pianism.

[2] At the end of the 1950s, Trzaskowski began working with Polish cinema, arranging and recording music for the film Night Train (1959) by Jerzy Kawalerowicz.

[2] In June 1962, Trzaskowski moved to the United States with a new composition of The Wreckers: Dąbrowski was replaced by Adam Jędrzejowski, and Karolak by Michał Urbaniak.

In the years 1965–1970, Trzaskowski took part in jazz workshops under the patronage of the Norddeutscher Rundfunk radio station in Hamburg, writing around 20 previously unheard songs for the event.

In 1972 he won the 3rd prize (the 1st and 2nd were not awarded) in the composition competition of the Radio and TV Committee and the Polish Composers' Union for his ballet music Nihil est.