Thanks! What I was missing is that for "V chord" I was thinking G not G7, and G doesn't have a tritone. (He did say "with the flat seven" which sounded like an

Thanks! What I was missing is that for "V chord" I was thinking G not G7, and G doesn't have a tritone. (He did say "with the flat seven" which sounded like another chord entirely, but that just means seventh chord.)