Can you explain why this works? Take Cissy Strut. (For reference, I refer to parts in this video.) Play the main riff (0:25-0:45) in C-. Then, at the B section (0:46-1:06), change key to Ab-. Back to C- for the head. The sax guy I played with last night called this one out mid-song while he continued to blow over the change. It sounded great. But why does the C- to Ab- work? It's a weird interval. Ab is the 6 of C-. We played through the modulation without a pivot chord. Is there something special about modulating to the 6? As opposed to any other interval?