Music Appearing in Pictures Folder

Just copy all the items that are in the wrong Library & paste them into the correct one which I assume is your Music Library.

When you are satisfied that all is well & all files are in their right places you can delete the old ones from your Pictures library.

The advantages of using Copy & Paste, rather than Cut & Paste, or dragging them across, is that if anything goes wrong during the process you still have the original intact, so you can try again.

To prevent files being put in the wrong Library, make sure you save them to the correct Library.

Just modify locations to remove the folders that you don't need to include in the library.

Click where the arrow is pointing to in the screenshot.

You should be able to delete them from your Picture Library without them being deleted from your Music Folder.

Try deleting just one of them & see if it has also deleted the one in your Music Library. If not you can delete all the others. If it has been deleted then you should be able to recover it from the Recycle Bin.

If you extremely worried about deleting them you could copy them to a USB thumb drive, then delete them & if necessary you can copy them back to the right Library from the the thumb drive.