Duplicate tracks and merging
DISCO's merge feature is a great way to deal with duplicate files. Merge lets you remove duplicate tracks while keeping the tracks' place and history in your lists.
How to merge tracks
To merge tracks, select the tracks you want to merge using multiple select, and choose Merge from the In the Merge pop up.
You can then choose which track you want to be your 'master track' – the copy of the track that will remain after the merge. You can check the metadata of the different tracks by selecting them in the top right section of the window. When you've selected your master track, click Merge tracks:
After the merge one track will remain, but it will appear in any playlists all previous duplicate copies showed up in.