I did something stupid

[TheMusicGeek]

I have two routes with two independent systems. Due to the distance between us we buy disks independently and once every few months we “synchronize”. Since it has been quite a while I decided to try to merge the files. I installed his hard drive (USB) in addition to mine and used the merge option to attempt to import his songs into my hard drive. What in fact happened is his songs merged into the song book but remained on his hard drive and were not imported. In my infinite stupidity I copied his songs directory into mine, assuming that duplicates would be ignored. What I ended up with was a mix match of songs verses songbook data and I ended up deleting the songs directory and restoring it from the backup. Now I am back to square one with my original problem/question. Can I import kma data between two hard drives or is it best to just load the disks one at a time every few months?