hello and welcome to the forum,
it should backup only the most recently changed files.
but there is another kind of backup, a forever forward incremental backup.
each time you run it, it keeps the latest files in the current folder.
and older files that would have been overwritten are moved the the archive folder.
rclone sync D:\Music GDrive:/DESKTOP-NH3JT7K/Music/current --backupdir=rclone copy D:\Music GDrive:\DESKTOP-NH3JT7KMusic\date
here a read of this forum post, there is a script called archivesync.bat.
and no matter you do you should test with flag
--dry-run
https://rclone.org/docs/#n-dry-run