I just talked with a guy at Marshall Grain here in Ft. Worth who just recently broadcast annual rye on a new clay soil dam at his place. Said it was already germinating. He didn't recommend doing a perennial rye.
And, it's too late to do common bermuda--we'll put that in next May, early June.
Plus I've got some "wild" grasses (Johnson and others that I don't know what they are) already on the back side slope. Got some wild flowers on there, too.