Thank you for the details of the issue you are experiencing with managing your music on your iPad and iPhone. Have you tried making separate playlists for each device and just syncing over that specific playlist?
The article below outlines ways to sync multiple devices with one computer. I recommend using the method of making a separate playlist for each device for the situation you described:
Sync devices to playlists
You may use multiple devices on a computer without creating multiple user accounts. To do this, you can set iTunes to update each device with only certain playlists. This method allows you to put all your music on, for example, your iPod and keep your iPod shuffle updated with only your workout music. Here's how to do this with iTunes:
- Create new iTunes playlists on Mac and Windows that contain all the music you want to sync to each device.
- Sync your device.
Note: iTunes for Windows does not support syncing multiple iPod devices at the same time.
Find the full article here:
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