Contents Intro I had an incomplete set of empty directories and they lacked my backed-up files. I found the backup that had the desired files, and the solution, as I suspected, was rsync1. Since it was music, mostly made into Opus files with abc2, I wanted to recover the files without the physical effort of re-ripping and converting them. Command rsync -a --ignore-existing ./Music/ ~/Music/ Footnotes 1 https://unix.stackexchange.com/questions/149965/how-to-copy-merge-two-directories 2 The original effort with opus files instead of mp3, including a full journey… https://tech.