The Xbox 360 is a versatile gaming console that allows you to enjoy a wide array of media outside of video games. Playing videos and music only requires inserting your CD or DVD discs into the Xbox 360's disc tray or connecting a USB device to one of the console's USB ports. Whether you are playing a video game or listening to music, you can reduce the on-screen content's volume from your Xbox 360 controller.
Push the Xbox Guide button on your Xbox 360 controller. This is the large green button in the centre of the controller. Doing so launches the Guide menu.
Use the D-pad or left stick to scroll the cursor to the "Media" section.
Scroll to the Media tab's music playback buttons. These are beneath the "Windows Media Center" option.
Scroll to the music volume button. Push the "A" button to activate. This is the rightmost button that features the volume icon.
Use the D-pad or left stick to adjust the volume cursor lower as desired. Doing so turns down the music volume in relation to the game volume.
Select the game's "Options" tab from its main menu to lower the game volume. This must be done from the game's menu, as the Xbox Guide does not control game volume. Choose "Game Volume" from the "Options" menu and use the left stick or D-pad to turn down the volume as desired.