I often have it playing in the background as I simply live in my house. It's not the only music I find helpful (along Shuhak's answer) but it 's the first to come to my mind and I happened to be listening to it when I read your question! :)
I think it depends both on personal taste and the situation (what got you uptight). For me, the same song will mellow me out one day, but on another it can invoke irritation or bring me to tears. For example, some days Pink Floyd "soothes" me, but on others Enya does the trick.
It's more than likely a personal thing and would probably depend on the immediate circumstances. I used to have this in my profile page, until the redesign, and I found it quite relaxing.