Er … no. There isn’t a single 12-bar blues ever written that’s in mixolydian. Look at those chord progressions: G, C, D7. Where’s the F natural in that? I would go so far as to say that if somebody ever did try to write a 12-bar blues in mixolydian, it wouldn’t be a 12-bar blues. It’s simply not idiomatic in that genre. (Just in case somebody comes back with “But I’ve seen a blues in G that has F naturals in”, yes you may well … and also B flats. They would typically be played against the F# and B nat respectively. It’s a blues thing - not to do with the church modes at all. You even get blues in E major that have B flats in …)
Oh, and by the way, I can’t speak so definitely about Country music, but I’d be surprised if there were many, if any, country songs in mixolydian. I’m willing to be persuaded on this one, though. Give us a link to one that’s in mixolydian …
