Maybe you have it paused... maybe the music hasn't started playing yet and you want to know if your ears are going to bleed when it starts.

This is especially useful when you have tunes that start out realllly quiet and then jump into loud music. You may look at the volume setting to confirm "no, the volume is fine, the music level is just really low". If you "go by ear" to move that low-level to something more audible, when the REST of the tune kicks in, you'll be feeling the pain.

D