If I do not wish to participate, how can I be sure that my music is not licensed by STIM to AI services?

The license only covers works from songwriters and music publishers who have explicitly given their consent. If you have not been directly asked to be included in the AI license, your music is not included.

As the market develops, STIM will maintain an ongoing dialogue with affiliated rights holders with the aim of gradually expanding the licensed repertoire base. For the time being, however, you can be completely assured that your music will not be licensed by STIM to AI services without your direct consent.