I discovered this song yesterday while listening to last FM.  It is a psychedelic classic rock song.  Click on the play button to listen to it.

Here are the lyrics:

There rides the rainbow demon On his horse of crimson fire Black shadows are following closely On the heels of his desire

Ridin on in the mist of morning No one dared to stand in his way Possessed by some distant calling Riding on through night and day

Rainbow demon Pick up your heart and run Rainbow demon Lives for his sword and his gun