I created my own Pandora station today, but I'm not satisfied with it. I added a real mix of music but I find that Pandora plays songs in little groups of like music, and then plays them alphabetically. It's as if the system looks for a pod of like songs and then plays them, then goes and looks for another pod, etc. I want my station to really mix from the whole pool, with great variety. How can I make the station shuffle?