The klapa music is a form of traditional Croatian a cappella singing. The word klapa translates as "a group of friends" and traces its roots to littoral church singing. The motifs in general celebrate love, wine (grapes), country (homeland) and sea. Main elements of the music are harmony and melody, with rhythm very rarely being very important. A klapa group consists of a first tenor, a second tenor, a baritone, and a bass. This type of music is very popular in Slovenia, where we often see these groups on big stages throughout the country. The Ljubljana shows will feature guest performances by Croatian pop vocalist Petar Grašo.