Can someone use my music on TikTok?

TikTok maintains two different music catalogs, and the distinction controls whether a use is authorized. The Commercial Music Library (CML) is pre-cleared for business and brand use, so business accounts and paid ads are generally limited to CML tracks. TikTok's general music library — the standard 'Sounds' catalog that personal accounts add from — is licensed only for personal, non-commercial user-generated content. A trending sound in the general library is not a commercial license. If a brand, agency, business account, or paid ad used a general-library song in a commercial context, that use is likely unauthorized and needs a separate sync license (composition) and master use license (recording).