Here's how you can delete all the music from your iDevice without using iTunes

  In iOS 5, Apple has implemented quite a few new functions and not everyone knows how to use a good part of them. Today I will show you how you can delete all the music from your iDevice and to do this you need to go to the Settings>General>Usage menu where you will find information about the space occupied by all the applications installed in your iDevices. Accessing the Music application menu you will see in the upper left a button called Edit which, as soon as you apply it, will open the option to delete all the music from your terminal.

  Although deleting music is simple, unfortunately once you delete it, you will not be able to recover it unless you have it available in iTunes installed on your computer.

Thanks to M.