I never use the Music app, I don't have any music on my phone, and I disabled background refresh and everything else I could possible think of. I read various threads on here about the Music app and did everything suggested. For some reason, the music app still consumed large amounts of battery in a short amount of time. Last night I charged my phone to 80% and and noticed a significant drop in the battery level after sitting idle for about an hour. See picture below. The recent deleted app was Music. I decided to remove the Music app from my phone and life appears to be good so far in terms of battery usage.