Soothing classical guitar playing, accompanied by a lovely bird song.
Meditation Bird Song
Such beautiful sounds... so calm and relaxing it just makes you sweep all your worries away :)
I listen to this at least once a week. I usually meditate on sundays (with sensestamps) and listen to this. After this I'm set with a good mood for another week!
This helps me while I do my math or any kind of home work