Similarity of Natural Minor and 
Melody Maker Special Tunings

Here's the relationship between Natural Minor (NM) and Lee Oskar Melody Maker (MM) special tunings.

Note that IMO the primary tone color you get from the MM is the Maj7 chord and note, rather than the dominant 7.

Here's a Melody Maker layout:
Hole: 1  2  3  4  5  6  7  8  9  10
Blow:[Eb G  C  Eb G] Bb[Eb G] Bb Eb
Draw: F [Bb D  F  A] C [D  F  A] C

And a Natural Minor layout:
Hole: 1  2  3  4  5  6  7  8  9  10
Blow: C [Eb G  C  Eb G] C [Eb G] C
Draw: D  G [Bb D  F  A] Bb[D  F  A]

The brackets '[]' and coloring show where the notes are the same.  Since the MM only modifies the first what-would-be draw C to a Bb, the other 2 C's on the draw don't align with the Bb's on the NM.  On the blow side there's the same Bb/C mismatch, but much the rest is the same after NM hole 1.

So, the Maj7 chord on the MM--the Bb D F A in holes 2-5 draw--is right there on the NM in holes 3-6 on the draw.  The Natural Minor actually has the Maj7 chord again! More than the MM... And, the Major6 and minor chords on holes 1-6 of the MM are there on the NM as well.  The major chord on the high end of the MM is a minor chord on the NM...

Anyway.. the point is, there's a lot of overlap between the two tunings.  Much of the flavor of the MM can be found on the NM.  AND, every chromatic note except one--the Gb (flat 6th)--is in the middle Bb scale (so-called by Lee Oskar 3rd position) of the NM tuning.  (The Db, E,  Ab, and B require normal draw bends.)