I'm honestly not even sure what 'music caching' is.
I copy all my music to a Google Play account. Then I can listen "live" when I have a connection, or download what I want to my Kindle for times when I won't be connected.

I copy all my music to a Google Play account. Then I can listen "live" when I have a connection, or download what I want to my Kindle for times when I won't be connected.