The article examines the main stages of the formation of Belarusian folklorists’ ideas about the variants and variative nature of folk songs in the period from the late 18th century up to the present. In modern folkloristics, variance is understood as a specific feature of folklore, which manifests itself in that works of folk art exist in variants. The problem of variance in the oral tradition is distinguished by its special multidimensionality and complexity; it can be oriented towards resolving most important issues of various nature that persist in folklore studies, and, above all, the problems of the formation, evolution and transformation of oral folk works. Four main periods can be distinguished in the process of forming the problem of variance in Belarusian folklore. First, it was empirically found that multiple variants of folk songs and different local styles and traditions did exist and that there were a number of factors that influenced the occurrence of song variants (place, time, environment, performer’s age and individual abilities, form of existence). Attention to the phenomenon of variants in Belarusian folklore grew in close connection with accumulated factual material and increasing level of theoretical thought. The variant comparison method has become a dominant one for studying problems of Belarusian and East Slavic folklore and for discovering specifics and regularities in the existence of folklore.