@GooglePlayMusic You keep answering your own question- and not mine. Ok, I get it, you want to ease uploading my music to your app. Not what I asked! I want to make personal music list and be able to upload it to other devices.
Thanks for the tag – do you mean creating your own playlist? You can access your uploads added to your playlist on other devices when you sign in to your account. It'll sync whenever there are changes to your library. More here: https://yt.be/help/KUNe