Standby battery drain, Music App

I seem to be getting somewhere around 10% battery drain per hour even on standby. I've not upgraded software recently because I'm still on iOS 9.1. It was working fine but mysterious Music App "background activity" is draining my battery even when my phone is not being used. I've already setup my phone so that it's not losing battery such as background refresh, manual email fetch, brightness to 50%, limit ad tracking, wifi assist off, cellular data and notifications off for certain apps I don't use, calibrated battery, etc. Anyone else seeing abnormal Music App usage in the background?