A frequent Subversive Guitarist topic will be note choice—specifically, ways you can substitute relatively interesting notes for relatively conventional ones. Let’s start as close to the bottom of the musical scale as you can get: with the lowered second degree, variously called the flat second, flat 2 (b2), or lowered second. Dropping the second scale degree by a half-step can add color and character to your playing with relatively little effort.
What is b2?
You probably know that the major and minor scales each have seven notes. There’s a whole-step (two-fret) gap between most of the scale steps. In major scales, half-steps fall between the third and fourth scale degrees and between the seventh and octave (a return to the first scale note, but eight scale steps above), as in Ex. 1.
Minor scales are more variable, but most often the half-steps fall between the second and third scale degrees and between the fifth and sixth scale degrees (Ex. 2).
So, if we lower the second degrees of the major and minor scales, we get the mutant major (Ex. 3) and minor scales (Ex. 4) shown below.
This simple scale alteration has massive theoretical implications. But let’s put theory on the back burner for now and just use our damn ears.
What b2 Does
Anytime a half-step appears between two scale steps, it creates tension. It often feels as if there’s an invisible gravitational pull trying to draw the notes together. Consider the gap between the seventh degree and octave in the major scale: When you play a melody that should resolve on the root/octave, but doesn’t, you feel the tension. This simple “shave-and-a-haircut” tune is an obvious example. If you delay the arrival of the final note in the phrase, its absence is almost like a physical ache (Ex. 5).
There’s similar tension around the half-step between the third and fourth degrees of the major scale. You can feel it if we add a couple of notes (Ex. 6). Here the seventh scale degree “wants” to pull up into the octave, while the fourth “wants” to resolve down to the third.
Even though it lies outside the formal major scale, the b2 has a similar gravitational pull, as heard in Ex. 7. You can feel how the Db note pulls us toward the root. As before, it feels frustrating when you delay the final note.
This chromatic scale degree can even join forces with the half-steps that occur naturally in the major scale (Ex. 8).
It doesn’t matter whether you define that penultimate three-note chord as Db7, G7b5, or something else. It’s the half-step relationships that create the progression’s tension and release. We’ll delve deeper into the theory and applications behind this, but for now, here’s the key point: The b2 has the tension of a coiled spring—until it resolves, as expected, to the root.
The same “magnetic force” applies in minor keys. Check out the simple melody in Ex. 9. Here in the key of G minor, the second scale degree is A.
In Ex. 10, however, we lower that A to Ab. It still makes harmonic sense, and you still feel the pull to resolve on G. It’s simply a darker, stranger way to get there.