How to use TouchCopy's Copy History
As a track is successfully copied, TouchCopy will mark the track on your iPod as copied. Whenever you connect your iPod to TouchCopy - TouchCopy will detect the music you have previously and successfully copied. This allows you to know which tracks have been copied and which have not.
Tracks will be marked with a icon under either "Copied" (you have copied the track), or "iTunes/Music" (the track is already in iTunes or the Music app on macOS Catalina or Big Sur).
Note that if you previously copied your iPod to your computer hard drive with TouchCopy and now you wish to copy your iPod to iTunes/Music (or the other way around) you should clear the history of copied tracks, as TouchCopy does not differentiate between history of copying to PC or iTunes/Music.