Try iPod.iTunes

iPod.iTunes was, and is, a lot of work and is therefore not free. You can try iPod.iTunes without registering to see it in action. You can register and buy an activation code here. Unregistered, iPod.iTunes skips about 50% of songs during synchronization (the exact rate depends on the contents on the iPod). When registering later, iPod.iTunes will transfer the rest of songs/playlists seamlessly to the iTunes library - thanks to it’s add-synchronization, without duplicates.

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