Hello @Corea Parks,
The feature to add music to blog posts using Wix Music is on our wishlist and can be voted for here: https://support.wix.com/en/article/request-adding-music-to-blog-posts-7459160
You'll be notified when it's available. The article also explains how to add music by embedding a music track (such as a SoundCloud track) using HTML code.
I hope this helps!