Is there a standard way of looking at a #9b13 chord, I mean as an extension, or stacking of a certain type of triad on top of another triad? If so, I don't see it - maybe there is something in an inversion or common voicing that I am not seeing. The application that prompts this - full disclosure - is the last chord in each chorus of - not a gospel song - Recordame. I recognize it as both a tri-tone sub of a possible Bb7, but also as part of a minor turnaround to the A-7 that starts each next chorus. Any thoughts?