I listen to music when I write stuff up and even when I am out and about. The genre is not really important though genres do tend to give me ideas for RP's like my Power to the Beat idea and Metal Maidens idea. At the moment, the Life is Strange soundtrack is really getting me going though usually I tend to listen to Aggrotech, EMB, Dark Electro, Soundtrack (Both Videogame/Movie) Metal (Various sub-genres).

The strange thing is I have written peaceful posts and RP ideas via angry and aggressive music such as The Fading, Hammercult, Arch Enemy, etc. I have also written aggressive and warlike posts and RP ideas via calming music such as anything from the Life is Strange soundtrack as an example which is basically licensed indie and original indie music. 

The spoken word from lyrics does give me ideas and feelings towards writing a post or RP idea as well. Cradle of Filth has given me many ideas and good posts though they are only one of many bands/artists who have done this. Psyborg Corp, Deathstars, D12 and many more have also done the same. As long as the music makes me flow it does not matter what type it is though rarely I do get stuck but it does not last too long.

Video Game soundtracks such as Mass Effect, Timesplitters, Life is Strange, Legend of Zelda, Loaded and many more are usually really helpful but lyrics in licensed music can be just as helpful. I remember being rather stuck and I listened to a few tracks and before I knew it I was writing away though this example extends to both original and licensed music. 

Strangely though not music-related the stupid stuff on the radio in Saints Row series gets my brain working most of the time but I don't do it that way much.