Currently Being ModeratedSep 1, 2013 10:41 AM (in response to teggles)
When you sync your devices, you should get a dialog that tells you that there is content on your device that isn't on your Mac, and also asks you if you would like to transfer that content to your Mac before you sync your device (otherwise the content will be removed from your device).
Clearly it sounds like you aren't getting this dialog. To get the dialog back, select your device and go down to "options", and click "reset warnings". That should bring it back, and be sure to tell iTunes not to transfer your content.
("Sync all music" and "back up to iCloud" have nothing to do with this.)