If you backup your music collection regularly, sometimes you need to delete a huge size of previous backup due to too many changes made onto the current library. MB's backup feature can handle that while backing up, but it takes some time, and your hard disc has to work a lot.
The worst way is to use Windows Explorer and move them to recycle bin. It could feel like taking forever depending on the size of your backup. Some clever command line solutions work better: "del", "rmdir", or "for" command with bunch of switches like /s and /q. But it's not the fastest way.
What I came up with to the task is "quick format." Yes, if you can format, why deal with each of the files and folders?
So if you're using a second HDD or an external HDD for backup, create a separate partition in it first. Of course, the size of the partition should be determined in consideration of the overall growing pace of your music collection. When you're doing an incremental backup, MB's backup feature handles it very well with a least amount of file writing. When you have to wipe out the entire previous backup, then it's time to get the benefit of "quick format".
Two added bonuses: by using a separate partition for backup, you have a much better chance of recovering your music collection when the HDD crashes because that space is dedicated to your music files only. Another benefit is your music files are less likely to be fragmented by the use of the HDD for other purposes and thus offer a quick access time when playing and updating them.