In a departure from his usually serious compositions in 1957 to 1963, Lutosławski also composed light music under the pseudonym "Derwid". Mostly waltzes, tangos, foxtrots and slow-foxtrots for voice and piano, these pieces are in the genre of Polish "actors' songs". Their place in Lutosławski's output may be seen as less incongruous given his own performances of cabaret music during the war, and in the light of his relationship by marriage to the famous Polish cabaret singer Kalina Jędrusik (who was his wife's sister-in-law).