I am happy you started this, as I did a search for "music" before I started a thread.
I have found that classical soothes my girls. If they are really fussy, quite often I can get them to quiet down by playing classical. I also play jazz for them, or stream Siriously Sinatra on sirius/xm. I keep a small wifi speaker under the roof just outside the run so I can easily play music to keep them happy.
When looking for information a few weeks ago, I found some articles on chickens and music. I take blogs with a grain of salt, but this one does cite, and link to, studies regarding chickens and music.