Dżem is a Polish blues-rock band. Ryszard Riedel, one of the most famous Polish vocalists, worked with the band. The band's name comes from English word jam (session) which has the same pronunciation as the Polish word "dżem", which means "jam" in the sense of a fruit preserve. The band's original name was "Jam" but before one of their concerts a woman made a mistake when she wrote their name, writing "Dżem". Their songs include "Czerwony jak cegła" (Red as a Brick), "Whisky", "Wehikuł czasu" (Time Machine), "Sen o Victorii" (Dream about Victoria), "Harley mój" (My Harley), "Mała aleja róż" (Little Rose Avenue), "Naiwne pytania" (Sappy questions), "List do M." (Letter to M.) and many more. They were the back-up band for Eric Clapton's concert in Gdynia on 14 August 2008.