Mute Action

I enjoy the music in GuildWars, but sometimes I like to listen to other music while I'm playing. For me to listen to this music, I have to turn down all the volume controls under options and then I can hear the music from my computer. If there were a new game action called "mute" that players can assign a key to, it would remove the hassle of changing the volume controls. Pressing this assigned key again would also reset volume controls back to where they were assigned by the player.