If you are using iMazing to manage your music, you will want to prevent iTunes from syncing with your iPhone, iPad or iPod every time you connect it to your computer.
There are two ways to disable automatic syncing in iTunes: you can disable automatic syncing for all devices, or for individual devices.
To disable automatic syncing for all devices (recommended):
In iTunes Preferences, uncheck Prevent iPods, iPhones and iPads from syncing automatically.
Mac: iTunes > Preferences... > Devices
Windows: Edit > Preferences... > Devices
To disable automatic syncing per device:
1. Connect your device to your computer and click the device button near the top left of the iTunes window.
2. In the left sidebar, select Summary.
3. In the main window, under Options, uncheck Automatically syncing when this iPhone/iPad/iPod is connected.
To ensure best results using iMazing music management do not use iTunes to manage music. iTunes sync will overwrite the changes you made in iMazing.