Pentatonic vs Diatonic

[Ryan H]

I never thought I would understand modes until just recently. I've been taking a Psychology class in college as an elective, and when we got to the topic of Memory, something clicked.

 

It's been observed that the average human can only remember 7 (+/- 2) pieces of information at one time. These pieces of information can be numbers, words, or sets of information with some meaning (like scale patterns, for example).

 

I could never recall how each mode related to the Ionian mode (Major Scale). I knew the Major scale; it had been drilled into my head. Information piece count: 1.

 

The Dorian mode is the Major scale with a flattened 3rd and 7th. Information piece count: 3.

 

The Phrygian mode is the Major scale with a flattened 2nd, 3rd, 6th and 7th. Information piece count: 7.

 

The Lydian mode is the Major scale with a sharpened 4th. Information piece count: 8.

 

The Mixolydian mode is the Major scale with a flattened 7th. Information piece count: 9.

 

The Aeolian mode is the Major scale with a flattened 3rd, 6th and 7th. Information piece count: 12.

 

And Locrian I never use so...yeah.

 

As you can see, if you take each interval as a piece of information, it exceeds the count of what the average human can remember. Even if you take each mode (including Locrian) as a piece of information, that's still 7 pieces, the limit of the average person.

 

So I found a more efficient way to remember the modes.

 

There are 3 minor and 3 major modes. Dorian, Phrygian and Aeolian are minor. Ionian, Lydian and Mixolydian are major. Locrian is half-diminished.

 

I know the Major scale and Natural minor scale by default. The Major scale is Ionian, the Natural minor scale is Aeolian. Information piece count: 2.

 

There's only 1 note different between the Ionian and Lydian, and the Ionian and Mixolydian modes. Lydian has a sharpened 4th, Mixolydian a flattened 7th. Information piece count: 4.

 

There's also only 1 note different between the Aeolian and Dorian, and the Aeolian and Phrygian modes. Dorian has a sharpened 6th, Phrygian has a flattened 2nd. Information piece count: 6.

 

I find 1 note in each octave easier to remember than 2-3 notes in each octave for certain modes. Opened up modes for me.

 

Hope that made some degree of sense.

 

-Ryan

[zigzag]

C Major Scale         C       D       E       F       G       A       B       C    Ionian Mode , 1st Mode of Major Scale
Interval              1       2       3       4       5       6       7       1
Steps                    W       W       H       W       W       W       H         W= Whole Step, H= Half Step
Fret Distance         0      2        4      5       7        9       11      12

                     C       D       E       F       G       A       B       C      
D Dorian Scale                                                                            2nd Mode of Major Scale
Interval              b7      1       2       b3      4       5       6      b7
Steps                      W      W      H       W       W       W       H       
Fret Distance         -2      0       2        3      5       7       9      10

                     C       D       E        F       G       A       B       C
E Phrygian Scale                                                                          3rd Mode of Major Scale
Interval             b6      b7       1       b2       b3      4       5      b6
Steps                    W        W       H        W       W       W       H
Fret Distance         8      -2       0        1       3       5       7       8

                     C        D       E       F       G       A       B       C
F Lydian Scale                                                                             4th Mode of Major Scale
Interval              5        6       7       1       2       3      #4       5
Steps                     W       W       H       W        W       W       H
Fret Distance         7       -3      -1       0       2       4       6       7

                     C        D       E       F       G       A       B       C
G Mixolydian                                                                               5th Mode of Major Scale
Interval              4        5       6       b7      1       2       3       4       
A Aeolian                                                                                  6th Mode of Major Scale
Interval              b3       4       5       b6      b7      1       2       b3
B Locrian                                                                                  7th Mode of Major Scale 
Interval              b2      b3       4       b5      b6      b7      1       b2

 

This took me an hour to get right and I'm not messing with it any more. As I said in the unedited post, if you play each one of the notes in these scales on guitar, you will see patterns emerge and it will make more sense. It is useful to know that the Aeolian Mode is that natural minor mode for the tonic major.

 

Theory is terribly difficult to explain in a forum like this because it is easy to make assumptions about how much is already known. For this stuff to make sense to everyone, the instructor must start at the very beginning. The fact is that, though it seems very complicated at first, once you get it, it seems very simple. And it is so much easier to see if you're sitting in front of a piano. Where I had, and still have, problems seeing things is due to the two half steps that occur between B & C and E & F. Plus, the whole system makes more sense to me seen as numerical intervals and fret distances instead of note names. And on guitar, I have to visualize the fretboard when visualizing a keyboard would be so much easier.

 

What is the point of all this. The point is that if you elect to select notes out of a scale from the chords in a progression, you can use these scale/modes for each chord. Also, knowing how a major or minor scale is harmonized can help you determine what mode fits with each chord in a progression. But you also need to know which notes in a mode are harmonious with the melody, and in the end, that is what really counts. If you have, for example, a minor seventh chord, that chord is comprised of the root (1), b3, 5, b7. If you look at that chart, you see that the Dorian, Phrygian, and Aeolian scales all have a 1, b3, 5, b7 in them, and depending on the melody notes, all are possible candidates for exploration against that chord using the root of that chord as the root of the scale/mode. Where that chord falls in the harmonized tonic key is also a clue. If anyone is interested, I can discuss harmonized major and minor scales, although harmonized minor scales are still a little tricky for me.

 

This chart is of modes of the major scale. There are dozens of other scales, but they are all derived from the major scale. Other useful scales- Pentatonic, Blues, Melodic Minor, Harmonic Minor, etc. Make up your own, or forget all of this and just wail... it doesn't matter.

[jdgm]

Anyone mind if I come in on this?

 

@Rabs - sorry to be pedantic mate, but neither 'Sweet Child O'Mine' OR 'Sunshine Of Your Love' are strictly speaking pentatonic. 'Sweet Child' outlines a D major and also implies G major (as the chords change beneath the riff) and 'Sunshine' is the D (minor) blues scale.

 

Look at the 5 black keys of the piano, in other words all the accidentals....with intervals of tone and minor 3rd. Start on any one and you have a pentatonic scale. Notice the minor 3rds are NOT adjacent.

Or - arrive at the pentatonic in this way; remove the semitones from the C major scale.

As it goes with the C major chord, we remove B not C, and F not E.

What is left is once again 5 notes with intervals of a tone or minor 3rd; C major pentatonic, C D E G A. Start this pattern from the A and you get (of course) A C D E G which is A minor pentatonic.

 

The rule for pentatonics in western music is they generally have intervals of a tone and minor 3rd, with the minor 3rds not adjacent as noted above.

The Ramon Ricker book on pentatonics is good as is Steve Khan's 'Pentatonic Khancepts' book.

 

Non-Western pentatonics are different - remember 'Within You, Without You'? The melody is based around a 5-note scale of I, III, IV, V, bVII. In C this will be C, E, F, G, Bb. Also the arpeggio of a Dominant 11th (Dom 7th with 4th added, NOT a Sus4 chord).

 

Regards!

[btoth76]

...'Sweet Child' outlines a D major...

 

Correct.

 

The main riff is in diatonic D major. At the ending Slash plays an E (12th fret high-E string). Just because of this E (2nd) we can assume it's diatonic, since He doesn't plays a B (6th) in it, which would make the riff definitely a diatonic riff.

 

Cheers... Bence

[quapman]

 

Try my suggestion. Find a backing track in A major and play G flat minor pentatonic over it.

 

 

Ok, so I did try this last night.

And while it's not in my wheelhouse(not a bad thing at all),, it did work.

Although I did find myself wanting end up on the A all the time.

 

 

Also played around with that chappers scale droning the root. That was interesting as well.

Thanks.

 

I wish I could retire so I could just play guitar all day..

lol.

[Rabs]

Anyone mind if I come in on this?

 

@Rabs - sorry to be pedantic mate, but neither 'Sweet Child O'Mine' OR 'Sunshine Of Your Love' are strictly speaking pentatonic. 'Sweet Child' outlines a D major and also implies G major (as the chords change beneath the riff) and 'Sunshine' is the D (minor) blues scale.

 

Errrmm.. I'll get my coat

 

 

It doesn't surprise me that im wrong as I know so little about this stuff.. I just thought they were pentatonic due to the shapes (like they fit in the boxes as such)..

 

Oh well.. Maybe I will just stick to making them :unsure:

[charlie brown]

Does it count, if you've only "heard of," these scales?!

 

CB

[BobF_]

I guess I need to get my guitar scale tape measure out ;)