Once you get your head around the fact that you can play all the different modes simply by starting any major scale on any note other than the root, your improvisational prowess is stepped up a gear, and you gain a certain amount of freedom on the fretboard… IF you know your major scales in all 12 keys. If I want to use C Dorian, for example, I simply play the Bb Major Scale starting on C and bang – C Dorian; but what if my knowledge of Bb Major is a little shaky? In turn, my knowledge and use of C Dorian is also going to be a little shaky… so what’s wrong with this picture?
My knowledge of C Dorian depends on my knowledge of Bb Major.
This might work well in keys you constantly use such as C, A, G, E, and D (no coincidence), but when it comes to fairly common modes found within fairly uncommon keys, problems arise. Granted, it’s exactly the same major scale pattern in all keys, but those less common keys will throw you off.
One way to mitigate this is parallel thinking.
As far as scales and modes are concerned, this involves learning/knowing the modes off the same root: C Ionian, C Dorian, C Phrygian, C Lydian, C Mixolydian etc., plus any other scales you want to learn, instead of the diatonic C Ionian, D Dorian, E Phrygian, F Lydian etc. The advantage here is that you go straight to a C Dorian pattern (or set of intervals) that starts on C rather than Bb, which affects your choice of notes much more than you’d think. If I’m improvising using C Dorian, I want to be thinking how everything relates to C, not Bb.
Let’s say you want to use C Phrygian and C Aeolian in a solo to add some variation over a C Minor chord. In the parallel system, the only difference between these two scales is the 2:
C Phrygian – 1, b2, b3, 4, 5, b6, b7
C Aeolian – 1, 2, b3, 4, 5, b6, b7
On the fretboard, it looks like this:
Meanwhile, if you want to access these scales using the parent scale method, C Phrygian is the 3rd mode of Ab Major, and C Aeolian is the 6th mode of Eb Major. Again, chances are that you’re not very familiar with the key of Ab Major; Eb major is a little more commonly used but most players will end up scratching their heads.
Therefore, in parallel terms, if you know a couple of patterns for Phrygian and Aeolian, you shouldn’t have too much trouble accessing these modes in any key; while in diatonic, or parent scale terms, it can be a headache.
Need to Know Basis
Another advantage of parallel thinking is that you can choose the modes you want to use, rather than feeling obliged to use all of them. As you progress on guitar, you’ll be drawn to certain sounds over others; for example, and depending on the style of music, the Dorian mode is my go-to minor scale, while my go-to major scales are Lydian and Mixolydian. I rarely use the Phrygian mode, unless I want that particular sound—but it might be more relevant to your music.
If you look at the C Phrygian and C Aeolian patterns above, you’ll see that they’re what I call ‘playable patterns’, or patterns that fall nicely under your fingers. If you’re trying to fish these kinds of patterns out of Ab Major and Eb Major respectively, and you’re not intimate with those keys, you’re going to have your work cut out. Staying within one octave also helps you get your ear around the sound of the mode you’re trying to play, rather than that wishy-washy sound you get when you’re playing Ab Major but wanting it to sound like C Phrygian; again, you have to make a real effort to see things from the point of view of C and not Ab – headache.
What to Do Next
If you want to practice and incorporate parallel thinking into your playing, first of all seek out some comfortable scale patterns that fall nicely under your fingers, and which are movable, such as this D Aeolian pattern:
If you’re not quite ready for parallel thinking, check out these articles to get you making music from the parent scale idea: