Combining multiple hard drives without getting duplicates

I have 3 hard drives of my music. I recently bought a 1 TB HD to combine them all. I was told that when I copied a folder, Windows XP would ask if I wanted to replace that folder. If there were 3 songs already there, those 3 would not be copied, but the missing songs to that album would be added.

What happened was I got mutiple copies of songs, 3-4 simetimes, and my hard drive is at maximum capacity.

Any and all help is appreciated. Thanks!