Are 6 flats the ultimate? Heck no, The key of Cb has 7 flats. Take Janie's six flat list and add a Fb to it. You can also play in 7 Sharps if you want. Key of C#. Now this should be a really bright key. ( F#, C#, G#, D#, A#, E#, B#) Anybody play in those keys? Cheers, Steve Barbone