When adding new music, do I need to Rescan the folder with music, or do I just scan the folder that has the new music in it?
you can re-scan the full folder if you want. M1 will not re-import data, it won’t make a new/duplicate song card. so, if you scan and select all of the audio files in a folder, after the import of an entire folder that was previously imported, the screen will show something like: Tracks in Folder 1200: Tracks imported: 5. it won’t over-write what it already has. it will, however, change the drive\path\filename in the M1 CART and FILE fields, if you have moved the file from one folder to another since your last import.
alternately…after M1 has scanned the folder and you see all the song title in the right-panel…you can manually select just the new files that you want to import and import only the new ones.