Which minor scale/mode do you use to harmonize the chords, when improvising in minor key?

Question

When improvising in minor key (let's say classical harmony, non-modal), I guess the minor melodic scales (asc. and desc.) are used to play, well, the melody (hence the name melodic?). Or is the harmonic minor scale also used sometimes for the melody?

But which scale do you usually use to harmonize the chords?

Scale                              Example in A minor        Chords voicing  
---------------------------------------------------------------------------------------------
Natural = Aeolien = Melodic desc.  A B C D E F  G  A         i iib5 III   iv v VI   VII               
Minor harmonic                     A B C D E F  G# A         i iib5 III+5 iv V VI   viib5             
Melodic asc.                       A B C D E F# G# A         i ii   III+5 IV V vib5 viib5             

The name "minor harmonic" suggests it is the one used to do the voicing of the chords, is that correct?

If so, how do handle problems like the G / G# dissonance:

• chord = V (fifth degree of minor harmonic = major), G# is present

• melody uses minor natural (=melodic desc.), G is present

More generally, without overthinking the problem too much (I probably do), what are the rules you use, consciously or unconsciously, to decide which scale to use for both the melody and the chords voicing, when you improvize in minor mode?

Answer 1

Neither harmony nor melody comes first. Sometimes you have to change one to accommodate the other. For example: V7->i resolves stronger than v7->i. This is because of the tritone (G# and D in your case) that creates tension, and the leading tone G# that wants to resolve upwards to the tonic. But if you want a weak solution, you can use a minor v->i instead.

This means you would have to avoid playing the G over this chord. Nobody will tell you that you may not descend over the melodic minor in the same way you went up. Jazz musicians do this a lot. Otherwise, you could modify the melody to use neither G nor G#. Playing the harmonic minor for melodies create a distinct sound due to the augmented second. I would not recommend this unless you are going for that specific sound.

Answer 2

When improvising over anything, it's important to be aware of what the prevalent chord is (and where it's likely to go), so in that situation, I keep all options open. As in key Am - A B C D E F F♯ G G♯.

In a jazz or blues situation, I'd be happy using the G♮ or G♯ over an E bar. Although in a classical situation it would need to be G♯ over E bars, but G♮ would work elsewhere. And there may even be a C♯ that finds its way in, over Am, just before going into a Dm part.

Avoid notes are well worth considering (avoiding!). That F♯ is one to not play during Dm bars, although in an Am piece, D major may be featured, at which point it becomes very much a 'play me' note.

Answer 3

How you view this may depend on the task at hand. If you are engaged in a composition task I'd follow classical rules and lean to the use of melodic minor, since that's what it's there for. But you have asked about improv.

I generally agree with Tim's statement about keeping all options open, to that end chromatic works. The real issue is do you understand the song you are soloing over. You have asked us to provide you with "the rules" for this or that and in fact there are no "rules". What you need to do is know the song you are improvising over and borrow from the main theme (variation on a theme is improv). To try and distill this creative process into a simple to follow mathematical rule does not do justice to music or improvisation. I am well aware of the current trends to do this but my experience was different, having learned it sort of "on the job" in the late 70s - 80s.

Rather than thinking that the harmonic minor harmonized "these chords" think about whether you want to express a musical idea that emphasizes the cadence to the minor key. This does NOT have to be accompanied by the presence of the relative V7 chord every time. You, the artist, are free to paint that idea. People often use these altered scales even when the corresponding chords are not present in a tune. As an example think of So What by Miles Davis. It's a one chord vamp with a chromatic change to another one chord vamp. Given that it was written with the intent to be played with the Dorian mode (transcribe Miles' solo for details) you'd be a fool not to use Dorian. But many players will inject the b6 (D aeolian) or even the Blues scale. I have also heard great players slip a major 3rd into a minor progression. The hallmark of the Blues is the juxtaposition of b3 and b5 over the 7th chord. You can even force these tones over a Maj7 and make it work. The fact is, if you transcribe great solos you will often see violations of "the rules" all over the place. What counts is evolving a simple musical idea, using sequencing and repetition, phrasing matters too. Keep in mind that you can always create creative extensions to chords at your leisure.

If you are trying to get a handle on improv methods then I'd recommend getting inspiration from original song.

If you are just working through changes blindly I'd recommend not doing that until you've devoted some time to transcribing and other pursuits to learn by example how it's done.

I would highly recommend the approach advocated by Jerry Coker in "Improvising Jazz" and keep a book of licks you create and practice working these licks into tunes.

As for the specific G/G# dissonance? It depends what you do with it. The G would work over the V7 of the minor key just fine as part of a blues lick. Are you really planning on just walking through one note per chord? In the specific example you cite the combination would be V7(b9) which is a very common chord (unless I've misunderstood your example).

Answer 4

It depends on what chords are used. It depends on what the original melody was - that will have SOME influence on your improvisation I hope, else how are you improvising on THAT song rather than just a chord sequence? @Tim's point of going back to the idea of 'avoid' notes is a good one. Your choice is wide open, but probably don't lean TOO heavily on the major 3rd in a minor tonality!

Answer 5

There are some procedures that have been used over the years for composing in minor keys. Which procedures you use (if any) depend on your ideas, whether the improvision is vocal or instrumental, the style of music, etc.

Common Practice theory treats the minor mode as a single scale with two mutable notes (notes 6 and 7). I'll try to use Arabic numerals for scale steps and Roman numerals for chords build on these steps. I'll also use the term "natural" and "raised" to represent which version of steps 6 or 7 are meant.

If the underlying harmony is primarily tonic (I chords mostly) then melodies tend to use the raised form of both steps 6 and 7 in ascending passages and the natural form in descending passages. Sometimes this combination is called the "melodic" minor. Using the raised 7 is pretty common too in non-vocal music. (Just the raised 7 is sometimes termed the "harmonic" minor as the raised 7 occurs in the V7 chord.) Often the possibilities are mixed. Using the melodic form for bass and the harmonic form for the melody is fairly common though it may produce a cross relation (lower 7 in the bass with a raised 7 in the melody).

If the underlying harmony is primarily subdominant (iv or ii0 chords predominately) the natural forms of steps 6 and 7 are often used in either ascending or ascending passages. (There are exceptions if the composer thinks it sounds good.)

If the underlying harmony is primarily dominant (V or vii0 chords), the raised 6 and 7 are common in both ascending or descending passages. (The raised 7 alone is also common.) An arpeggiated V chord is also used (even in vocal music as the augmented second is easier to sing on a single chord) as scale steps 2,4,6,b6,7 (repeated if desired) makes a dominant ninth (V9) chord.

About the only thing avoided is using the raised 6 step as an upper neighbor of step 5 (composers like chromatic neighbors). The augmented chord on step 3 (3, 5, #7) is avoided in earlier music but does appear in the late 1900s and later. The raised 6 step seems to mostly occur as a passing tone between 5 and the raised 7. It will occur in ii chords (and #4 occurs in II or II7 chords when used as the dominant of V).

These are tendencies and there are lots of exceptions. The biggest exception (as noted above) is using melodic minor patterns in the bass against melodic minor patterns in the melody.

Answer 6

There are many different kinds of answers, so I'll add mine. Long answer. I'm not sure I can write a TL;DR for this.

First of all, the fundamental idea of how I look at the three main dimensions of music - harmony, melody and rhythm - is that they can be completely separate and independent only in theory. In practice, whenever you create a sound, any sound, it has some consequences and implications in all three dimensions. A melody implies or outlines some harmonic possibilities, and how you place your melody notes in relation to the perceived rhythmic pulse, affects the perceived implied harmony.

Whenever you play any note, you poke a stick somewhere into the chords machine. And whenever you play a chord, you change the playfield for a melody line, setting walls and obstacles to bump into. So what is a scale? Does a scale "exist" if you aren't playing all the notes at the same time? In my opinion, the most important way to see scales is just as a reference grid for reasoning about where sounding notes are or could be. Another way to use scales is as construction kits or palettes for obtaining certain harmonic effects. Particularly in songs in minor keys, you'll notice that whatever scale you try to see as the only construction kit or note-set for the song, it doesn't seem to be enough. Natural minor ... doesn't work work this song, there are out-of-scale notes here. Harmonic minor ... doesn't work either, it still leaves some out-of-scale notes!? "What is the scale of this song???" If there's one misconception, myth or wrong idea with how a lot of people see music, that's "every song is in a scale". No! A scale is just an initial starting point, and then things start moving.

How do I improvise in a minor key - exactly the same way I improvise in a major key. I think about and improvise ALL dimensions of music I possibly can, and how much I'm able to do in each dimension depends on things I cannot change and decide on the spot (particularly my skills are a restricting factor). For example if there's a full backing track, it sets a lot of decisions in stone. But if there's only a drum beat, I can create a completely new song. If there's a melody without chords, which is basically the situation in free-form accompaniment of songs, it leaves most of harmony and rhythm open for re-inventing. (just don't confuse or upset the soloist/choir/congregation)

A practical example.

• Let's say the song is in A minor, and you want to move from an Am chord to a Dm chord. You could just do the jump, Am - Dm. If these are the only sounding notes, I guess you'd say that the scale is A natural minor, even though nothing was explicated about a G note.
• But you could do a "V-I into Dm" modal mix: Am - A7 - Dm. What happened to the scale? At least the C note was sharpened in your harmony during the A7 chord?
• How about Am - Gm6 - A7 - Dm? Now during the Gm6 chord your B is flattened, and during the A7 the C is sharp ... and then during the Dm these temporary changes are cancelled.
• But were those the only changes to the scale? How about if you use notes from the A half-whole diminished scale over both the Gm6 and A7? Now you have both C and C# - or is it Db. But you also have D# and E and F#.
• ... but since not a full scale was explicated as notes, were those really the scales, the full scales and nothing but the scales? It's subjective! The composer or improviser might be thinking about a scale, but if they explicate it only partly, the rest is left for imagination. Even with chordal instruments, you usually imply things a little bit, and when playing unaccompanied non-chordal instruments, implying harmony is kind of the whole point. You might think about a full story with detailed situations, but as a story-teller you carefully (or instinctively or "subconsciously") decide which details of the picture you need to reveal to the listener. Do you explicate the harmony loud and clear and extensively in a "for dummies" way, all possible notes must sound, so the listener isn't allowed to draw incorrect conclusions? Or do you allow for some feeling of mystery?

Some more examples:

• If the song is in A minor, and there's a fixed melody but it doesn't happen to use the F note for awhile, I can use a backing D or Bm chord, creating an A Dorian feeling.
• If a rhythm section is playing Am and I get to improvise the melody, I can still outline a D major chord for the same A Dorian effect.
• If the melody has come to rest at A and I can improvise backing chords, I might play a chord sequence: C, B, Bb. If there's a soloist and they hear these chords, they have to react - for example on the Bb chord they'll most probably want to avoid playing a B note.
• If the song is sitting on an A minor tonic, I might play an Am6 or Am maj7. Why? Because I like how those chords sound relative to an A tonic.

If I had to describe what I think about when improvising, I'd say that I think of fully extended chords as my target points - basically the sound of an entire scale. But the scales are created, composited from parts! I throw notes and chords into the soup, and a scale is created. What a scale is called ... is irrelevant because they are being molded like clay all the time anyway.

Answer 7

I listened to various songs and practiced on the piano after reading the other answers.

Here I share my observation on the famous song "Ne me quitte pas" of the Belgian songwriter Jacques Brel. We can find the three above-mentioned scales: natural minor, harmonic minor and melodic minor ascending.

• The first verse goes something like this (transposed in Am):

    i    i      iv      V
    Am   Am/G   Dm/F    E
  or
    i    VII    VI      V
    Am   G      F       E
  
    [---------------]  [---]
      natural minor     harmonic minor 
     (only G, no G#)       (feat. G#)
  

  In this pattern (very common in many songs), it seems that one possibility is to use:

  • harmonic minor on the V (G# is required to have the major fifth degree)
  • natural minor elsewhere (G everywhere)

• The verse "Moi je t'offrirai" (0'50") uses a melodic ascending minor scale: E E F# G# A , which contrasts suddenly with the beginning of the song, by creating an optimistic feeling.