ENThe study discusses features of musical scales in Lithuanian traditional vocal performances. Manifestation of the equidistant model of musical scale and its interplay with diatonic thinking are considered. Three samples representing three different ethnomusical dialects (54 songs, in total) are examined: the methods of diatonic contrast and clustering are applied in the processing of results of the acoustical pitch measurements. The evaluation of diatonic contrast shows that the song examples resembling the theoretical equidistant scale prevail over those resembling diatonics. The cluster analysis reveals certain groups of the scales characteristic of the examined dialects.