Things I wish my music teacher had taught me at school: Part 2
Scales
In part 1, I looked at how chords are constructed, in particular the importance of the third and the seventh. This leads to four very important chord shapes: if the root note is C, then you get:
- C∆ (major 3rd, major 7th)
- C7 (major 3rd, minor 7th)
- Cm7 (minor 3rd, minor 7th)
- Cm∆ (minor 3rd, major 7th)
But what are the other notes of the scale that we can use with these?
7-note scales
Most of the interesting scales, and the ones you are almost certainly familiar with, have 7 notes. Since there are 12 semitones in an octave, this means there are five intervals of a full tone, and two intervals of a semitone. Here is how a standard C major is constructed:
But given a root note, a third and a seventh, that’s not the only way we can fit notes in between to make a 7-note scale.
In the previous article, I observed that the perfect fourth over a major chord has a jarring sound. Can we fix that? Yes we can, by sharpening the fourth:
This scale even has a special name: the Lydian. It’s different to the normal major scale, but still has a major third and major seventh, so it fits with our C∆ (Cmaj7) chord shape.
Now, this might seem weird when you first hear it. And definitely don’t try to play “Twinkle Twinkle Little Star” with a Lydian scale: it sounds completely wrong.
But in many contexts this is an extremely natural scale. In fact, the sharpened fourth is perhaps the most beautiful note you can put over a major chord. Try it.
Modes
The next question you might have is, “is this a new scale I have to learn to play”? Well, look at the C Lydian scale again carefully. Have you seen a scale before, which has all natural notes except an F sharp?
Trust me, you have.
It’s just the G major scale — starting on the 4th note!
In fact, you can get a whole series of scales, just by starting major scales on different notes. These different variations are known as modes. They have been known for millennia, and they were named by the ancient Greeks. Here is the full set:
+------------+-------+-------+---------+----------------------+
| Name | Start | Third | Seventh | Comments |
+============+=======+=======+=========+======================+
| Ionian | 1 | Major | Major | Standard major scale |
| Dorian | 2 | Minor | Minor | Major 6th |
| Phrygian | 3 | Minor | Minor | Minor 2nd |
| Lydian | 4 | Major | Major | Augmented 4th |
| Mixolydian | 5 | Major | Minor | |
| Aeolian | 6 | Minor | Minor | Minor 6th |
| Locrian | 7 | Minor | Minor | Diminished 5th |
+------------+-------+-------+---------+----------------------+Some of these scales are major (that is, they have a major third), and some are minor.
For example, if you play a C major scale starting on the second note (the D), you get the Dorian mode. This has a minor 3rd and minor 7th, and a major 6th. It’s the scale you use when playing “What shall we do with the drunken sailor?”
The Dorian mode just gives the pattern of notes and intervals: it doesn’t have to start on a D. If you want to make a Dorian scale that starts on a C, you have to work out which major scale has C as its second note (that’s B flat), and then play a B flat scale starting on C:
Seventh chords
Things get more interesting when you look at a chord like C7, which has a major 3rd and a minor 7th. (Technically that’s a “dominant seventh” chord, but if someone just says “seventh”, that’s probably what they mean).
In the tables of modes above, there’s only one which has a major third and a minor seventh: the Mixolydian. It is the same as the obvious solution: take the major scale and flatten the 7th.
(Pop quiz: what scale do you already know that has all naturals but a B flat?)
But it turns out there are lots of other, really interesting scales to connect the major third to the minor seventh: this is where much popular and jazz music gets it rich harmonies from.
If you take the Mixolydian and sharpen the fourth, as we did with the Lydian, then you get my favourite scale of all time:
This scale doesn’t have an official name like the Greek modes, but “Lydian Dominant” is commonly used. It pops up in all kinds of places, like the theme tune to The Simpsons:
At first glance, that’s a really weird scale. It has both a sharp and a flat. Surely you can’t have seen this scale before?
In fact, I bet you have! But you might have to look carefully to work it out.
Answer: this is actually the same notes as the G melodic minor scale, but starting on the fourth note — that is, the fourth mode of the melodic minor scale.
Therefore, in principle, we have also have seven modes of melodic minor to work with. In practice, there are two others that are commonly used. One of these is the seventh mode:
Sometimes called “Super Locrian” (because it’s the same notes as the Locrian but with flattened 4th), this is more commonly known as the “altered scale”, since every note apart from the root and third is different to the major scale.
From a classical theory background, I found this astonishing at first. This scale has all the wrong notes! Not only that, but it seems to have both a minor third and a major third at the same time!¹
Is it possible that you can use this to build chords and music that sound right? Yes: it works great². Funky even. Just make sure, as I said earlier, to keep either the third or the seventh as the lowest note of the chord.
Of course, this chord and the associated melody or improvisation will probably want to be using the same scale, to avoid sounding discordant. (But anything goes, if you play it with enough conviction).
The other is the sixth mode, which works over a minor 7th chord with a flattened fifth — also called “half-diminished” and given the shorthand symbol ø.
This one is also similar to Locrian, but with a major 2nd instead of a minor 2nd. You’ll find this commonly in sequences such as Cø — F7 — Bbm.
Other scales
Although I said that the most interesting scales were 7-note, I’ll mention a few others briefly.
There is one 6-note scale: the whole tone scale.
This does also fit the seventh chord: it has a major third and minor seventh. But it has a weird, alien feel, with all those dissonant tritone³ intervals, and doesn’t get used very much. It’s the scale that the Clangers would use when walking downstairs.
There are two 8-note scales: the diminished scale (“whole-half”), and its second mode (“half-whole”). They have alternating tones and semitones; the names tell you which way round they go.
These are actually quite useful. The half-whole scale is yet another option for seventh chords: the lower half is like the altered scale, and the upper half is like the Lydian Dominant.
If you remove the limitation that scales can only consist of tones and semitones, then you get more possibilities. These include the pentatonic scale and its minor pentatonic mode. Add a note to the latter, and you get the infamous blues scale:
Try playing it over this chord⁴:
If this has piqued your interest, there are plenty of books and online resources which go into more detail.
Conclusion
This was a whistle-stop tour, and I necessarily left some things out (there are some other chord shapes, like diminished chords and major 6th).
But in short, here are the two things I wish I’d known earlier in my life:
- Chords are fundamentally built from the root, third and seventh. Then you can add any other notes from the scale (apart from Aunt Dolly).
- For a given root, third and seventh, there are many more scales that work with them than the ones I learned in classical music theory.
Thanks again for reading!
¹Observe that D sharp and E flat are essentially the same note. There are real problems when “spelling out” the notes in this scale: the way I chose has two D’s (a “flattened 9th” and “sharpened 9th”) and no F — but maybe I should have put F-sharp instead of G-flat. A true 7-note scale would have D-flat, E-flat and F-flat, but that would have looked even weirder, since the major third would turn into a flattened 4th. Or should I have used C-sharp and D-sharp (as it’s a mode of C# melodic minor)? Then I’d have A-sharp for the 7th, and either two C’s, or a B-sharp for the root. It’s messy.
²If you’re interested, there’s a reason it works so well. Try playing the C7alt chord I showed, but with F# as the bass note instead of C. The C7alt scale has the same notes as the F# Lydian Dominant — my favourite scale. The 3rd and 7th notes of C7 are the same as the 7th and 3rd notes of F#7, and the root note of one is the sharpened 4th of the other.
³Also known as augmented fourth, or diminished fifth.
⁴You can hear this in Kelly Blue, from the album of the same name by Wynton Kelly, when the opening head is played for the second time (at 0:45 here)
