Lojze Slak Band, along with singing group Fantje s Praprotna, were performing from 1964 until 2011. Their repertoire encompassed well over 500 songs, 341 of them vocal. Considering lyrics, songs could be classified alike folk songs, that is why Lojze Slak is supposed to be the most distinguished folk musician playing diatonic button accordion in Slovenia. In this thesis, lyrics of his songs are classified by theme into four main groups: love songs, existential songs, patriotic songs, and impressionistic songs. These themes are further divided into 40 subgroups, e. g. gatherings and celebrations, longing for home, unrequited love, lovers physically apart, various professions… each of them containing various topics and subtopics. Main characteristics of every topic group is analyzed. In the songs, love (166 songs) and existential questions (131 songs) are topics prevailing by far the most, while some patriotic (26 songs) and impressionistic (15 songs) topics could be found, too.