Coastal assault without music
As you start flying off along the coast in the Hornet you got at rally point alpha, music starts up. It's rousing stuff, but if you fancy battling without music, simply wait for about six and a half minutes until the music ends. The Hornet can hover in place while you go off and have a banana sandwich or something. Having invested that time in waiting, you may like to now get a checkpoint to save, so you'll be able to replay your music-free assault as often as you like. You can get one just ahead before attacking anything.
Warning: If you're going to be playing without music, preferably don't jump into the level at rally point alpha as the game doesn't seem to provide all the usual ambient sounds such as whistling wind. That can make things sound very muted and unnatural if you ever get out of the hectic battling, for example if you land on a ledge or island for a bit of long-range shooting on foot.