No, I would not repeat a backup if nothing had changed. You are probably increasing the chances of a problem with unnecessary backups.
For example, what if the main music drive had developed some corrupted files and you didn't know about the problem? In this case, you'd simply be wiping out a good backup copy and replacing it with the corrupted one.
If you're just worried about the condition of the backup drive, you can always run a disk integrity test on it
I keep two backups of my music drive and back those up only incrementally (i.e., only new music gets added. Existing song files are not replaced.) One of the backup drives is kept off-premises in the event of a fire, windstorm or theft at my home.
For example, what if the main music drive had developed some corrupted files and you didn't know about the problem? In this case, you'd simply be wiping out a good backup copy and replacing it with the corrupted one.
If you're just worried about the condition of the backup drive, you can always run a disk integrity test on it
I keep two backups of my music drive and back those up only incrementally (i.e., only new music gets added. Existing song files are not replaced.) One of the backup drives is kept off-premises in the event of a fire, windstorm or theft at my home.