Finding a scale from power chords

Question

I'm sorry if this question was asked thousands of times. I'm learning basic music theory and how chords are constructed from intervals etc. and I'm trying to apply this knowledge to the music I'm playing. When I write a riff I don't think about all theory behind, I'm just taking what sounds good to my ear. So I've ended up with the riff which has the following progression of powerchords

E F G Ab

Now, it doesn't fit to any scale that I know, the Ab is really annoying me. For example if I had to play a solo over this, what could I use?

Also if I'd like to transform those powerchords to regular chords, I would go by ear as well, so I'm not really sure if there is a trick to know which powerchords should be major or minor let's say. It depends on scale but if I don't know the scale at first it becomes a bit a trial of error journey for me.

What am I missing ?

Updates based on answers:

As @Peter notes, E F G A flat fit into F minor scale. This is true, however B note is not a part of F minor although E powerchord has B as its fifth ?

Answer 1

It's a little difficult to know what you're asking. The trivial answer is that it's an eight-note scale, E-F-G-Ab-B-C-D-D#; you really can just call any collection of notes you want a scale and try to compose music with it. I could call this "Phrygian flat-four with an optional raised seventh", or plug it into the scale finder and tell you that it's "Mixotharyllic", but none of this tells you anything useful.

If you're asking what key you're in, I'd tell you you're in E Phrygian, and that the last chord is a dissonance which resolves back to the E. Not every chord in a song comes from the scale(s) nominally associated with its key, and as a soloist you will have to deal with this reality; jazz musicians often work with a different scale over every chord because of how liberally the genre borrows.

In your particular case, the simplest possible route would be to stick to E Phrygian, and just let the A-flat sound exceptionally dissonant over it; I get the impression this is metal or crust punk, where that sort of dissonance can sometimes be expected. With only a little more effort, you could take on an entirely new scale for the A-flat, the most obvious thing to do would be to repeat phrases you played over the G, transposed down(!) a semitone. A halfway point between these options would be to stick to Phrygian, but spend most of your time over the A-flat on F, B, and C to avoid dissonance; you'll need to learn to do this sort of thing anyway, not every note in a scale is consonant with every chord in that scale.

I would go by ear as well, so I'm not really sure if there is a trick to know which powerchords should be major or minor let's say. It depends on scale but if I don't know the scale at first it becomes a bit a trial of error journey for me.

Again, there's no reason your chords need to fit within "the same scale"; even in the most traditional tonal theory, the minor key has three different scales associated with it.

According to my Phrygian interpretation, your first three chords "should" be E minor, F major, and G major. The A-flat, with both possible thirds in the scale, could be either. The conservative choice would be minor, because it contains the tonic's fifth; but you could really run with the "dissonance from outside the key" idea and add any non-conventional notes you wanted.

Going with the octatonic scale interpretation, the F should be minor and the E could be either; or, if you're going by ear, my main piece of advice would be to, instead of playing a chord and seeing if it sounds good, try to hear in your head what you want the next chord to sound like and work out how to play that.

I'm trying to apply this knowledge to the music I'm playing

It's entirely possible that the music you're playing doesn't conform that well to what is commonly called "music theory"; a recently-popularized hint is that "music theory" often means "the harmonic style of 18th century European musicians". That's not to say it's useless, but it's certainly not the tool I would use to discuss, e.g., all-major chord progressions in psychedelic rock. The main advantage "traditional music theory" has over other bodies of theory is that it's old, so there is a large amount written on it to a relatively high standard, which newer bodies of theory often not really fostered within academia lack.

Answer 2

You don't need to get stuck to a single scale. You can use more than one at the same time, change scales or play notes out of the scale on purpose.

I see this as a mix of C major and C harmonic minor scale. Because you use G, G# and D#

Now, it doesn't fit to any scale that I know, the Ab is really annoying me. For example if I had to play a solo over this, what could I use?

You can change scales between G and G#. You can change the 5th of the last power chord (i stead of G#, use G#5aug, or 1st inversion of E chord). You can change the last chord (G#) with E and let the bass guitar play G# for you. Many possibilities

Answer 3

"Also if I'd like to transform those powerchords to regular chords, I would go by ear as well, so I'm not really sure if there is a trick to know which powerchords should be major or minor let's say. It depends on scale but if I don't know the scale at first it becomes a bit a trial of error journey for me"

There is no rule. You can do anything in music. All rules are made to be broken. If you want to follow a scale pattern, look the notes of the chords you chose and write them down in order to find out a scale that fits most. In you case, there are C, D, E, F, G an B. All these notes belong to C major scale. So the chords would be Em, F, G and E/G# (1st inversion of E chord)

Answer 4

I feel your pain, Ab chords can be annoying, lol. The way I see this is E, F and G can all be seen as chords (Em, F, G) or modes derived from the C major scale. This approach will allow you to play the notes of one scale over those 3 chords, E Phrygian, F Lydian and G Mixolydian.

The Ab is a special case and can be approached a few different ways depending on what sounds good to you. A few suggestions: If it sounds minor to you, you can use a minor pentatonic or a minor scale. Even an E major scale (Basically an Ab Phrygian scale) might work since Ab (G#) is the iii chord in E. If you hear it as major an Ab major or Lydian scale might work for you over that chord.

Answer 5

What [scale] could I use?

Single scale option

All of the answers generally revolve around noticing which notes are in the chords you're playing. @PauloHenrique was most explicit about this. So let's take that solution a step further. Looking at the roots of the chords gives:

X:0
T:chord roots
K:none
L:1/4
E F G _A

Similarly, the chordal fifths give:

X:0
T:chord fifths
K:none
L:1/4
B c d _e

Combining them gives us a very intriguing eight-note (octatonic) scale.

X:0
T:complete scale on E
K:none
L:1/4
E F G _A B c d _e

Running this scale over the power chords gives a sound I personally like a lot, but when you hit the Ab chord, start the scale on F, because starting on E against the Eb doesn't fit the overall sound.

In fact, this scale works even better if you start it by running over the chord fifths. In that case you don't have to adjust when you get to the Ab chord.

X:0
T:complete scale on B
K:none
L:1/4
B, C D _E E F G _A

Two-scale with transposition options

There are two cases where three of the power chords fit a single diatonic scale: E F G and F G Ab. The other two cases can't fit a single diatonic scale, because they contain two consecutive half steps: G Ab E contains D Eb E and Ab E F contains Eb E F.

E F G

All three of these power chords will fit into C major. I recommend using B locrian for the best result, because that way the root and fifth (B and F) correspond to chord tones (5 of E, Root of F, 3 of G).

In that case, I like C minor for the Ab chord, as it mirrors the half-step shifts in the chords, especially from G to Ab.

F G Ab

F Dorian

Here we encounter F minor, as has been discussed, but in the form of Dorian, to accommodate the D in the G chord. For compatability, use E phrygian on the E chord to set up the F and G chords plus the D in the next scale.

C natural minor

Use B Phrygian against the E chord. It's gives a sense of a C major/minor shift, but the B-F# perfect fifth sounds better against the E chord than B-F.

C harmonic minor (starting on B)

In this case, use B Locrian over the E.

Partial scale options

Rather than try to fit a complete scale to the chords, you can find subsets of scales that work well, often avoiding some of the "bad" notes that don't fit one chord or the other. Try running either of the main four-note subsets of my first solution over the entire set of power chords: E F G Ab or B C D Eb.

What am I missing

I don't think you're really missing anything. There are rules of thumb like power chords tending to sound minor and examining the complete collection of notes to derive/build scales, but in the end it's trial and error to find what you like. To construct triads, you can then extract them from the scales you've chosen.

However, in this case, I find triads limiting. As soon as you add the third to these chords, you create conflicts that generally restrict your options for scales/melody.

Answer 6

As has been already said, the notes (E F G A flat) fit into F minor scale. There is another connection, that the first and last of them together form an E maj7 chord. Powerchords have built-in ambiguity, as they are neither major or minor, and also the upper note can be treated as being like a harmonic (it is actually an octave too low, but for some purposes this can be ignored).

You will need to see what works yourself, but you might start by thinking of the A flat/G sharp as linking with the E chord. The final march in Prokofiev's Peter and the Wolf uses your theme, though with slightly different harmony (and in a different key).

Answer 7

In rock and pop the minor scale and the minor pentatonic scale are most commonly associated with power chords. Sometimes the minor harmonic is also used.

In your case, I would imagine that any of those chords, if they last long enough (e.g. one or more bars) would go well with the corresponding minor scales.

On the other hands, if some of those chords are next to each other, you should decide which ones are passing chords, or color chords, and which ones are the real tonal centers, and then use the minor scales of those tonal centers.

Of course this is not a dogma, but it's a reasonable starting point, you can then experiment with variations from this starting point and settle on what sounds best to your ear.

Answer 8

The first thing in trying to determine the key of a piece of tonal music, is to focus on the most important thing in tonal music: the root note of the piece of music.

The root note is the note where tension is resolved, the "home" of the musical sequence. Although there are many situations where you can guess it from a written representation of the music, it is ultimately determined by ear.

Without hearing your riff (or having an elaborate written representation), I have to make an educated guess. If I just play each chord in sequence for the same duration, I clearly hear E as the root note. The sequence sounds very phrygian to me because of the F powerchord.

My approach to soloing over this sequence is similar to that of @PeterSmith. I mainly use the E phrygian scale and replace the notes of the scale which clash with the A♭ powerchord with A♭ and E♭.

So this would be my first-order theoretical analysis: E phyrigian with A♭ as a borrowed chord to increase the tension before resolving to the root chord (again very similar to what @PeterSmith wrote).

For a more sophisticated analysis, we could note that the root notes of the powerchords indicate a mixture between the ordinary phrygian scale and the phrygian dominant scale which has a major third instead of a minor one. But the perfect fourth (A) isn't part of any of the chords, so it would be sensible to take the A♭ as a flattened fourth. This leaves us with the phrygian ♭4 scale which is a mode of harmonic major (see wikipedia for details). The 5th of the A♭ powerchord (E♭) would still be a note which isn't included in the scale. Its presence could be explained as a filler note which is used to get a similar sound for all chords. Without it, we couldn't play the last chord as a powerchord.

Let me stress that a more sophisticated analysis doesn't imply a better approach to soloing. Often using a simple analysis with additional heuristics based on what sounds good is the better approach.