Puredyne/Add Applications to the menu
Adding an application to the Audio category 
In our case we will add din (music software) to the Applications Menu under xfce4:
First, create a .desktop file via Create Launcher (right click), one can assing an icon and then when finished, it will appear on our Desktop.
To have it showing up under the Audio menu entry then, simply copy it over to:
after that run this on a terminal:
it will appear under the entry labeled: Other
To make it appear under the Audio entry simply edit the .desktop file and add the following line:
Re-run the update-menus command (as above).
That's all, took me a while to figure it out since the xfce4 methods are a bit of a mess.. Thanks krgn for the help.