This is a quick note on a John Stowell video, giving a summary of the idea he describes and then extending it a bit. It's pretty much the same general approach I advocate in my Arpeggio and Scale Resources. Commenters on the video express some confusion about the presentation so I thought it might be helpful to boil it down to a summary and then couldn't resist adding my own twist.

Stowell's Suggestions

Here's the clip:

The idea is to take a C7 and superimpose a minor-major 7 arpeggio on it. To extend this idea, we can fill in the minor-major 7 arp with either the Melodic or Harmonic Minor scale. I strongly suggest working with the arps first, then filling in the extra scale notes later.

Here are the four minor-major 7 arps that can go on C7, along with the non-chord-tones they contain relative to the C7:

• C#m Maj 7 (b9, #5)
• Bb Maj 7 (b9, 11, 13)
• Gm Maj 7 (9, #11)
• Fm Maj 7 (11, b13)

Filling in the notes of Melodic Minor for each of these gives the following modes:

• C#m Maj 7 --> Altered
• Bbm Maj 7 --> Dorian b9
• Gm Maj 7 --> Lydian Dominant
• Fm Maj 7 --> Mixolydian b13

Each of these is a different sound that needs to be internalised, of course, and each works in different settings. Most famously, the Altered and Dorian b9 are most comfortable when the C7 is functioning as the V in a V-I or V-i. The other two generate a lot less tension and work well when the C7 is going somewhere else, or even when it's a point of rest (as in the first bar of a blues in C). Getting these into your ears is much more important than remembering the names.

Using Harmonic Minor instead, we get:

• C#m Maj 7 --> Super Locrian bb7
• Bbm Maj 7 --> Locrian nat 6
• Gm Maj 7 --> Dorian #11
• Fm Maj 7 --> Phrygian Dominant

Other Possibilities

For fun, I then took a look at p.96 of my book to see what else I might try with minor-major 7 arps. The ones we know about are b2, 4, 5, b7. I would generally want to avoid mixing altered and unaltered versions of the same extension (e.g. mixing a 9 and a b9), although maybe that's something I'll experiment with in the future. In this way I came up with my own quartet of minor-major 7 arps that can be substituted onto a C7:

• Em Maj 7 (#9, nat 7)
• F#m Maj 7 (b5, b9, 11, 13)
• G#m Maj 7 (#9, nat 7, b13)
• Am Maj 7 (#5, 13)

These are definitely a bit more tricky than John's examples, because they don't come from familiar scales. Because of the presence of the nat 7, I feel like the E and G# versions work better on a CMaj7 than a C7, so I'll discard those for now. Let's see what happens when we combine the other two with the notes of the C7 arpeggio (in the second case I marked the 2 note with a ? since it's missing):

• F#m Maj 7 --> C Db E F Gb G A Bb (mode of Pavani add b6)
• Am Maj 7 --> C ? E G G# A Bb (mode of Neapolitan?)

Sounds to me like there are some cool sounds hiding in here for those willing to dig into them.