Kryl moved to Prague in 1968 as an assistant at Czechoslovak Television. In his spare time he performed his romantic and satiric folk songs in numerous small clubs. When the Warsaw Pact armies occupied Czechoslovakia on 21 August 1968 to suppress the Prague Spring reform movement, Kryl released his first album. The title song "Bratříčku zavírej vrátka" ("Keep the Gate Closed, Little Brother") was composed spontaneously on 22 August 1968 as an immediate reaction to the occupation. The album described his perception of the inhumanity of the regime and his views on life under communist rule. The album, released in early 1969, was banned and removed from shelves shortly after, but this could not prevent the songs from getting around the audience and becoming cult hits.