SUMMARY
The article presents the results of research into the influence of intralinguistic and extralinguistic factors on the phenomenon of variability in Slovene music terminology. Examples of variability in current and in older textbooks are presented. The analysis of terminology was conducted with the help of two linguistic corpora produced using the Sketch Engine tool. The corpora consisted of textbooks for tuition in music theory subjects in Slovene. We showed that terminological variation in these textbooks has existed a long time and is linked with the level of specialisation of the terms and with the process of terminologization. We have also referred to some other factors that in the past were responsible for the phenomenon of variability.