Scale Recommendation for Tricky Key Change

Question

I'm playing a pretty tune, which calls for a solo on the following chords:

Cm G7 C Fm

A♭ Cm G Cm

As you can see, the key temporarily changes, shifting the tonic chord to major before its returns to minor.

I'm looking for a method to play around these changes. My first impression was to focus on C harmonic minor (C, D, E♭, F, G, A♭, B), which would let me comfortably play around almost all of the above chords. When the measure for the C chord comes up, I would need to accent the major 3 note (E) absent in the scale.

But maybe there's another, better way. How does one approach soloing with this key change?

Answer 1

It is clear that this progression is modulating to Fm, the IV of Cm. Although the G7 is the V7 of Cm, indicating C harmonic or melodic minor I think it is clear that you will hear the change to C maj leading from G7. Now, the C is the V of Fm, and you could pass through C7 on your way there. The point is that one option is to play F harmonic minor starting as soon as G7 chord. In fact the entire first line could use Fm (or harmonic and melodic variants). This reminds me a bit of All of Me, a standard. Even though it's in Cmaj and the very first chord is CM7 the next chord is E7, then A7 passing to Dm. You could pass through each diatonic mode matching chords as you go by the whole first bar works well with D harmonic min, or even A harmonic minor. The maj 3rd in the A7 does not clash with the minor mode, the combo sounds bluesy.

The Ab could be taken as the rel Maj of Fm. Even through you start and end on Cmin try playing with Fmin and hm.

The following works imo (I've played it over your progression).

Cmin G7 play C hm

(C Fmin Ab Cmin) play F hm

(G Cmin) C hm

Keep in mind that you don't need to "accent" every chord tone or even get to them. You could get by with minor pentatonic or blues scales, it does sound bluesy. I would take some time to find common tones that thread through the changes or some part of them.

***** Correction *****

To add to this, another option is G phygian (C min but thought of differently) as that has the minor 3rd of F in it. If you add the B natural in the right place it sounds like a scale used in Spanish flamenco music (kind of harmonic phygian (I made that up)). I guess my advice would be stay away from matching chord to mode, that tends to create more work than necessary. You can fit a single mode over it and just use voice leading to catch the "out" notes. Since these are all leading tones you could play through them without exactly matching them. In other words by ignoring the F natural you create interesting tension while making your life easier (win win).

Answer 2

I wouldn't call that a key change, unless the C major chord is held for half a minute or something. :) It's simply a temporary scale or mode change, "borrowing" a V-I (or V-i) motion from F minor. In the key of F minor, the dominant-tonic chord combination is C7 - Fm. You can expand on that idea by playing a Bbm or Bbm6 chord on top of the C major - that's even more stuff borrowed from Fm key, like iv-V-i from F minor.

There's one thing that won't work, and that's trying to fit any single scale on top of an entire progression like that. It's better if you can twist the modal feeling elastically all the time, and you already found out that your chord progression moves through different harmonic feelings, so there won't be any one-scale-fits-all solution.

Edit: I forgot the dreaded pentatonics. For example C minor pentatonic might actually fit over everything - but to my defense, the word "pretty" was mentioned in the question, so that rules out a pentatonics-for-them-all approach. ;)

Some scale ideas for each chord

• Cm : C natural minor, C harmonic minor, C melodic minor, C dorian, ...
• G7 : C harmonic minor, C melodic minor, G half-whole diminished,
• C : F harmonic minor, F melodic minor, C half-whole diminished
• Fm : C natural minor
• A♭ : C natural minor
• Cm : same as before
• G : same as G7
• Cm : same as before

However, instead of playing entire scales, overlay or outline other chords on top of the backing chords. The other chords inevitably create some scale/mode feeling. Here are some ideas for chords to outline:

• Cm : (alt. 1, C natural minor) : all diatonic triads in Cm: Cm, Ddim, Eb, Fm, Gm, Ab, Bb
• (alt. 2, C harmonic minor) : Cm, Fm, G
• (alt. 3, C melodic minor) : Cm, F, G
• (alt. 4) : Cm, Db

• (alt. 5) : Cm, D major

• G7 : (alt. 1) : Cm, G, Fm6, Ab, Bdim7

• (alt. 2) : Cm, G, Bdim7, Fm6

• (alt. 3) : Bdim7, G, E, Db

• C (alt. 1) : C, Db, Edim7, F, Bbm6

• (alt. 2) : C, Bb

Etc. I may have made some mistakes with the chord list, but the point is that instead of first deciding an entire scale and then playing notes and chords from that, you can play chords without thinking so much about the scale. Who cares what scale it is - you cook your own scales and change it all the time. On top of a backing Cm chord you can overlay ... Eb, Ddim, Dm7, F, Gb, A, D7, Db, Adim, G7, Bbm6, ... each of these creates a feeling and changes the mode very elastically. Someone might say, all the chords are "from" a scale and in a way it's true, but another perspective is to say that combinations of chords create a scale.

Answer 3

You can just improvise (play around) on the scale of Cm using the lead tones B in G7 and E in C7

as this progression is nothing else than

i-V-(V/iv)-iv

VI-i-V-i

in C minor.