Melodic Bend is designed to play the major/minor scale (and the other five modes). The major/minor scale is configured in a linear fashion as opposed to a blow-draw setup. The ten hole glissando across the draw reeds sounds much better than direction changes do. It's legato, smooth sounding, not choppy. It's also easier to do and can be played as quickly as you care to play it. Then what we want is bends for expessiveness. Melodic Bend provides all the bends. You can bend to and from every note of the major/minor scale. This makes it really sing. Further, we can travel between the bent notes with ease. Example, the A on draw 8 can be bent down to G then we just move the harmonica to sound the F on the 7 draw whole step bend. It pops out right on pitch as it's bottomed out/at it's stopping point. We could then move to the E on the 6 draw half step bend in the same fashion, then let up on the bend and hit the F on draw 6. This isn't a difficult maneuver and it sounds wonderful. The travel between the bends opens up vast musical vistas. 

 Another feature of this harmonica is it's chromaticism. Any scale conceivable can be played comfortably with solely blows and draws.

A B major scale is configured across the blow reeds. These notes are also represented in the half step bends giving us even more options for creativity.

So we have our tonic all lined up on the draws giving us nine trills and a ten hole glissando for a smooth, silky sound that can be played very quickly and easily. We have all the bends for our tonic and we can travel between the bends for maximum expression. And the five accidentals C#, D#, F#, G#, A# are conveniently located on the blow reeds and the half step bends for mass chromaticism.