Liz Carroll's tunes rock.
This is one of her more simple ones. Its simplicity was the reason I picked it today because I was on a field trip with a Water Quality class taking samples of a river at different points along its path and comparing flow, turbidity, and other chemical and physical changes it underwent. It was highly depressing. I live in the Rockies. So the river started out clear, pristine, and cold; the perfect climate for the native trout that spawn here. Along the way it was diverted, withdrawn for irrigation, and sucked dry at some points. By the time it ended, it was depressingly greenish and brown in a channelized "canal:" a humiliated river.
So I was a little down when I returned home so there's nothing like some lovely music by Liz Carroll to make things better. Her tunes + dark chocolate = everything's ok again.