In the following we build a tonal system on the 7-degree melodic minor scale. Melodic minor differs from the major scale only by one tone, namely the minor instead of the major third. But this has serious consequences:
MM1 - ImMaj7:
The ImMaj7 chord formed from the 1st, 3rd, 5th, and 7th tone is a minor chord with a major seventh.
MM2 - IIm7:
From the second note, here the D, i.e. C melodic minor from note D, the following scale MM2 results:
The IIm7 chord formed from the 1st, 3rd, 5th and 7th tone is a minor seventh chord. The scale corresponds to the Dorian mode with the exception of the b9 instead of the 9.
MM3 - IIImaj7#5:
From the third note, here the Eb, i.e. C melodic minor from the Eb note, the following scale MM3 results:
The IIImaj7#5 chord, here Ebmaj7#5, formed from the 1st, 3rd, 5th and 7th note, is a Major7 chord with an augmented fifth.
MM4 (Mixo#11 oder Lydianb7) - IV7#11:
From the fourth note, here the F, i.e. C melodic minor from the note F, the following scale MM4 results:
The IV7 chord, here F7, formed from the 1st, 3rd, 5th and 7th tone is a dominant seventh chord. Except for the b7, MM4 is identical to the Lydian mode, which is why it is often referred to as Lydianb7 in English-speaking countries. However, since it is used as the dominant scale, the name Mixo#11 is more appropriate, because apart from #11 it is also identical to the Mixolydian mode. The usual use of the IV7#11 is as a so-called secondary dominant as a replacement for the dominant on the fifth degree. We will look at that later.
MM5 - V7:
From the fifth note, here the G, i.e. C melodic minor from the note G, the following scale MM5 results:
The V7 chord, here G7, formed from the 1st, 3rd, 5th and 7th tone is a dominant 7th chord.
MM6 (Locrian9) - VIm7b5:
From the sixth note, here the Ab, i.e. C melodic minor from the Ab, the following scale MM6 results:
The VIm7b5 chord, here Abm7b5, formed from the 1st, 3rd, 5th and 7th note, is a semi-diminished minor chord with a diminished fifth (b5). MM6 is identical to the Locrian mode except for the 9, therefore it is also called Locrian9.
The following scale MM7 results from the seventh note, here the B, i.e. C melodic minor from note B:
The chord to be formed is the so-called altered dominant seventh chord with the options b9, #9 and b13. It is usually on the fifth level and can be resolved to major or minor.
Resumé melodic minor:
The following chords and scales can be derived from the melodic minor scale:
A characteristic feature of the melodic minor scale is that it contains three dominant seventh chords. The dominant seventh chords at the 4th (Mixo #11) and 7th (altered) degree contain the characteristic #11.