You're worried about a battery that lasts for 3-5 days? o_o

You'd be lucky if a laptop lasted 8 hours with moderate use on a powersaving feature. I usually leave my device unused for 2-3 days and have to recharge and it's "semi" brand new. Be happy it lasts as long as it does!

Listening to music drains battery life a bit more than if you left it alone, but I can't say for if battery does better with WiFi off while listening to music since I never have WiFi off and can't/won't test it as such.

Jesse~