Without further ado, here's how it works. We'll start with the Ddim7 from the Keyboard Chord Decoder No.1. To associate it with a dominant chord, let's drop one of its notes a half-step—or borrow the note from the diminished seventh chord a half-step below—say the B to Bb; this gives us a Bb7chord, so we've put a Bbin the bass. Next, we can play the Ddim7 in root position over that Bbin the bass, and it'll sound pretty good; but let's use a Drop 2 voicing to make it sound better. Drop the second note from the top of the chord down an octave; this puts the Abdown onto the bass staff, making a nice shell voicing in the left hand. Cool. Now let's apply our simple borrowing system to our Ddim7 in Drop 2: Let's borrow an F# from the diminished seventh chord a half-step above, which gives us the first notes of the chord in this example, which if you get all analytical, could be thought of (as long as you think of enharmonic spellings) as an Abmin7b5 over a Bb. The Abmin7b5 is from the family of II chords in the "chord above" in the Keyboard Chord Decoder, and it relates to the Db7 chord from the family of V chords in the "chord below." Remember: chords from these related families can be mixed and matched freely. So what about that E? Taking all the notes of the Drop 2 voicing into account, we now have an E7 over the Bb, and E7 is indeed from the family of V chords in the "chord below." With the F at the end of the bar, we return to our Ddim7 chord in Drop 2 voicing, and then we resolve in the next bar to an Ebmaj9. Really, all we want you to think is this: Move the F up a half-step to a note from the "chord above," down to a note from the "chord below," and then back to the original diminished chord. Piece of cake, and you: get this nifty moving line that drives you to the resolution.