[iCloud Drive][1] is specifically to sync your data between machines, roughly similar to how Dropbox etc works.

Remove a file from one machine, it's gone from the others too.

'Documents & Data' was deprecated & is removed when you first convert your iCloud (Mavericks/iOS 7) storage to iCloud Drive.

***Alternative suggestion [untested]***

How about - as you don't mind having one copy locally, just not two, changing your iTunes Library location to a folder inside the iCloud hierarchy?

Move your actual 'Music' folder there & just point iTunes to it

![enter image description here][2]


  [1]: https://www.apple.com/icloud/icloud-drive/
  [2]: https://i.sstatic.net/F6XeX.png