With respect to your music app and/or gallery link: were you using a hard-coded default path to the original storage device and folder?
If so, you will need to change the path to direct the app to the new external SD card. I.e., path. Drive, folder(s), etc..
And a suggestion: always use Copy instead of Move.
If you copy then you have the opportunity to verify that the files are located in the new location and are readable. Before deleting the files in the original source location.
If you move and something goes astray, the files may be lost....