Blue Notes In Bluegrass? What You Need To Know!

Marcel Ardans

Blue notes get used a lot, you can find blue notes in countless genres and they certainly appear (sometimes too frequently) in bluegrass. But do you know exactly what a blue note is? Are you ever confused when people use the term? Does it have something to do with blues or jazz? Don’t worry, I’m going to cover what you need to know about blue notes when you play bluegrass in this blog post!

First we need a scale to start with, and though you may have mastered the major scale from this previous blog post, we’re going to be using the major pentatonic scale right now.

The good news is the major pentatonic scale is derived from the major scale. To think about the major scale let’s name the seven notes in the scale: 1, 2, 3, 4, 5, 6, and 7. Original, I know. These notes work great but not all of them evoke bluegrass over the chords that would be native to this scale. For example, the one chord. The notes in this chord would be the root, third, and fifth. From the major scale blog post you may notice that notes 3 and 4 would be a half step apart and notes 7 and 1 would be a half step apart. That means playing notes 4 or 7 over the one chord (1, 3, 5) could create some unwanted dissonance. So let’s get rid of notes 4 and 7 to save our ears some trouble.

That leaves us with just the major pentatonic scale, notes: 1, 2, 3, 5, and 6. You’ve likely seen the open position of this in G major if you play bluegrass.

The notes in this major pentatonic shape are safe, approachable and easy to use. You really can’t create any dissonance over the one chord with these notes. Only consonant sounds all the way, baby!

But let’s say we get bored of this sound and want to introduce some dangerous notes. Well we can borrow some dirty notes from the parallel minor pentatonic scale, G minor pentatonic. This scale will be comprised of notes: 1, b3, 4, 5, and b7.

This scale shape maybe less familiar but take a gander anyway.

This scale is going to create some more ‘acceptable’ dissonance. The minor third feels good as long as it resolves up to the major third or down to the second. The dominant seventh also feels good as long as we don’t hang on it (unless we want to imply G7). However, you may have noticed that one note from before snuck in, the fourth…

This is a trickier one to include sometimes but once again we don’t really want to hang on it and you can resolve it down to the third or up to the fifth. Otherwise you might be left with a hanging suspended feeling.

Here’s where things get important. We haven’t really created a new scale, per se. This is more like the G major pentatonic with some other notes that we can include when we want to. Maybe think of them as spices.

The pink notes are actually ‘blue notes’ borrowed from the minor pentatonic, the black notes are major pentatonic. Remember, minor pentatonic notes we don’t necessarily want to hang out on because they’re not as consonant as the major pentatonic notes. Leaning on them too heavily can imply different chords or create more of a blues feel. Both of those things are valid in certain contexts, just not really what we’re doing right now.

There is one more blue note to include though, some people call it ‘the’ blue note and it comes from a blues scale. You know, that one extra guy that sometimes slips into the minor pentatonic scale to make it a blues scale?

You’ve probably seen it in a scale like this.

That note is a flat fifth. This note is a very safe chromatic passing tone between the fourth and fifth and generally is used as a little highway between those notes. It also functions much better when you used it in a context where you are implying more of that blues sound.

It fits into our scale like this.

That takes us right to the end, which means all of the common blue notes are the minor third, the dominant seventh, the flat fifth and the natural four can party too because we’re actually kind of cool with him. The important thing is to not think of the completed scale shape as a scale shape. These are notes that like to be used in specific ways to invoke the standard hot bluegrass sound: Minor third resolved up to major third or down to the second, Dominant seventh down to fifth or up to the root, flat fifth is a passing tone to connect the fifth to the fourth, and the fourth works well moving to the major or minor third.

Can they be used in other ways? Yes! But normally that happens under extenuating circumstances. If you want more info on practicing this approach in a practical way you might check out my Bluegrass Improv Exercises video.

And lastly you may be saying, “Marcel, you’re practically using the chromatic scale at this point!” That is a solid statement, using specific rules and convention you can easily include all the notes of the chromatic scale over almost any chord. You can see a little more about that in my What Scales Do I Use For Bluegrass video.