I must say, making character playlists for getting inside a character's head before writing has been a superb idea.
And when a mix doesn't put me in the right space to write that character, it might be something wrong with the characterization or the playlist. 50/50 which but it's a neat tool to find it.
One is totally the kind of kid who'd listen to dubstep remixes of stuff and super emotive stuff like Lindsey Stirling, another is totally the kind of kid who listens to punk and nothing but. It's so good to find the headspace.