I'm pretty sure that sounds of different kinds are not too upsetting for chickens. My first flock was when I lived in town on a corner lot with lots of traffic.
On my country property the chickens have been unfazed by military helicopters overhead, the lawnmower, parties we've held, the crew that set the house in place, DH's power tools, and even a commercial-grade wood chipper that the tree service had operating about 5 feet from their fence when we had tree work done.
If they don't mind me singing Sabaton and Nightwish at the top of my voice while mowing or weed whacking around their fence I doubt they'd be disturbed by your soft, inspirational music.
I use those cheap solar lights that you stick in the ground to mark off the fence corners and other trip hazards. They're dim and aimed at the ground.
I also have a good headlamp for use in the coop after dark when doing off-the roost checks, etc.