AI Animators / Visual Artists - How Do You Select Music to Accompany Your Posts?

For the AI Animators / Visual Artists sharing your work on IG, I'm wondering how you select music for your posts? Do you source it only from the Instagram list, and if so, how do you find that process? Is it easy to find what you want? Do you mind using the same song that is used for other posts, sometimes tens of thousands of other posts?