Summary [Last.fm]: There are a few bands called like that. 1)Klan was a polish band formed in 1969 in Warsaw and headed by guitarist/vocalist Marek Ałaszewski. His mates were keyboard player Maciej Głuszkiewicz, bassist Roman Pawelski and drummer Andrzej Poniatowski. After releasing a self-titled E.P. in 1970, lyricist Marian Skolarski joined the band and composed “Mrowisko”.
In 1993, Allaszewski reformed KLAN who released an album called “Po Co Mi Ten Raj”. 2)KLAN is Czech Death metal band form Pardubice. Klan was founded in 2004 by Vihar (guitar). http://klan.xf.cz