To add to this, Android Kit Kat (4.4.x) prohibits applications from deleting files and directories from external storage unless the directory and nested files/directories were created by the application. I use iSyncr for other devices to sync from iTunes to my Android devices, and once they were all at 4.4, this became a problem they were trying to work around. For example, their Rocket Player music application couldn't edit tags of files copied to external storage by iSyncr, as they're separate applications.
However, if the device is rooted, then ES Explorer, Astro, and other file managers can edit/delete files anywhere on the card. Likewise, other applications can work with this as well. In addition, certain OEMs (like on my Samsung Note 3s) have stock file managers that can, in fact, edit and delete anything from external storage. So I used that to get rid of directories that hung up from artists being so "1337" with their bizarre character usage in the directory and file name properties. I was also able to delete those directories and files by connecting the device to a Windows machine and letting it delete the files in MTP and USB 3.0 modes. Once can, if necessary, dismount and eject the microSDHC card and just use it in a reader with a Windows, Apple, or *nix system that's aware of the reader and file systems and edit as needed without formatting.