The beginning of the article discusses phenomena related to the perception of music (specifically, the perception of pitch, musical scale and intonation) that can lead to misinterpretation. The result of the intersection of two emic systems (for example, the original tone system and 12-tone equal temperament) can be perceived as chromaticisms and ‘Greek modes’. Performance rules determine slight variations in intonation, depending on the melodic and harmonic context. This can also be misinterpreted as chromaticisms. The notations of the melodies of the songs of Lithuania Minor (from the collections of Christian Bartsch and Ludwig Rhesa) are analysed below, revealing manifestations of the aforementioned phenomena. The fact that chromaticisms and modulations in these notations arose due to misinterpretations is evidenced by the notators’ comments on the singers’ peculiar intonation, as well as by comparisons with the results of measurements of sound recordings of other musical dialects.