We have all heard the old saying that "music sooths the heart of the savage beast". Well, I don't know if that is true in every case; but it does seem to be true in some cases.
When farmers used to milk their cows by hand; they often had a small radio out in the barn and played soothing music as they milked the cow, because it did relax the cow and she would release the milk faster and easier. I did that when I had a milk cow; and it really does work.
Here is a really interesting little video showing how cats behavior changes as they listen to music. This music was written just for cats, and it has sounds that mimic a cat's heartbeat when it is calm and happy.
It is amazing to watch the change in the demeanor of these cats when the music is turned on.
