After copying music to the iPod, file names and folder names of the music files change to 4 characters with mp3 after them. Unfortunately, these do not identify the music file on an Android device or even the PC. Similarly, folder names too are changed. Could not find a way to get back the folder names, but use the ID3 tag Title field to change the name of the file to it. In short, something is better than nothing. Open a terminal window and install easytag with:
$ sudo apt-get install easytag <enter>
Next, start easytag and navigate to the folder where the mp3 files are stored. The files have an ID3 tag, but with just the Title filled in. This can be used as the name of the file on the hard disk.
Select View -> Scanner Mode and change it to Rename Files and Directories.
The field shows %n – %a – %t. Change it to %t as that is the title of the track in the ID3 tag. Click Scan files and the file name changes. Click Close and then File -> Save Files. Confirm to rename the file and it is done.