I assume the music stored in iCloud goes against the available storage, which will impact my ability to backup. Is this correct?

I am assuming my storage will fill up with music and I won't be able to backup. I already had this problem with my iPhone backing up photos (and videos) to iCloud then getting annoying messages that it couldn't backup. Of course, I would much rather have a backup so I had to disable backup of images.

Since they don't offer the ability to differentiate backing up photos and videos into the same environment that backs up the devices, I assume the same goes with music. It's probably all or nothing. I think I'll pass.