Sleepy Sleepers were found in 1974 in Lahti, Finland, by Mato Valtonen and Sakke Järvenpää. The band released 19 albums between 1975 and 1989. Their songs were laden with frivolous, sometimes scatological humor and jokes considered politically sensitive in post-war atmosphere of Finlandization. This led to problems getting gigs and, some of their songs being banned in then state-controlled mass media. Later, Valtonen and Järvenpää founded Leningrad Cowboys, when Aki Kaurismäki made movie Leningrad Cowboys Go America.