My intention is to simply scratch the surface of Music Theory in this post. Explanations are in the context of a rhythm guitar player named Jerry and a mandolin player named David jamming. My goal is to simplify this idea of scale degrees, having said this, this post is not for the very beginner. This post is for players who have put time into playing the major scale and understand each note in the scale correlates to one “scale degree.”
I argue that the 3rd and 7th scale degrees of any given scale have more harmonic importance. Lets look at some examples, sound clips will be added later for better understanding.
Jerry starts a song by strumming a C major chord.
David in turn is improvising on mandolin. He knows how to play his C major scale in order from practice. He knows all seven of those notes will sound good. They are:
1 2 3 4 5 6 7 1
C D E F G A B C
David might choose to focus on the notes, E as well as B. Because they correlate to the 3rd and 7th scale degrees of the chord.
Now Jerry switches to playing a C7 chord on guitar.
David needs to change his seven scale degrees to choose from. Each correlating to one note. The C7 chord is also know as a dominant 7 chord. This chord has a flatted 7th scale degree instead of a natural 7th. David has a full scale containing 7 scale degrees to chose from. From the regular C major only one scale degree has changed, the 7th has to be flatted. David then gets these notes below to choose from.
C D E F G A Bb C
These notes will all sound good. David chooses to focus on the E as well as the one note that changed the Bb. Bb being the flatted 7th scale degree and the only scale degree that changed from the simple C major scale.
Now Jerry starts a new song he has learned, it starts with the strumming of a Cminor chord.
David is coming up with his set of scale degrees to chose from in terms of notes he can play on the mandolin. Only one scale degree changes from the original C major scale. The 3rd scale degree needs to flattened. Also known as a flat 3rd.
C D Eb F G A B C
On mandolin David is soloing…Since a C minor chord is the sound being heard he might focus on Eb the flatted 3rd scale degree. As well as the 7th scale degree which is a B note
Jerry is now playing you a Cmaj7 chord, which usually appear in jazzier songs.
The scale degrees David uses as a template does not change. What changed is the chord Jerry is playing, he is including the 7th scale degree in the chord. Instead of a C major which is simply 1st-3rd-and 5th scale degrees, Jerry is playing the 1st-3rd-5th-and 7th scale degrees.
David on mandolin has the exact same template of scale degrees he used for C major over a C major 7 chord
C D E F G A B C
David plays the 3rd and 7th scales degrees. The E note and the B note. The B note being a defining part of Jerry’s major 7 chord sound.
In another jam session Cmin7 chord is being strummed by Jerry.
David knows a C minor 7 chord consists of a flatted 3rd scale degree, to make it minor, as well as the flatted 7th scale degree. David’s seven notes to choose from changes by only two scale degrees, the 3rd scale degree and the 7th scale degree.
C D Eb F G A Bb C
1 2 3 4 5 6 7 1
I hope this helps, if it doesn’t I am sure I can find a link to an article written by someone much better at describing this dry music theory stuff. When I say focus on the 3rd and 7th I am not excluding other notes. Many other notes sound great, these two just have a big part in chord construction. Also the 1st scale degree as well as the 5th scale degree are often played by a bass player, or by Jerry’s rhythm playing, plucking bass notes.
For my example above, I am in a way working backwards based on the chord you are playing. Any and all chords can be deconstructed, hence Chords with names like E7b9 or G7#5, these altered Dominant chords are not common in bluegrass, but are common in jazz standards. This makes for the argument that this trick is more important in jazz than bluegrass.
In chord charts it is useful to know that
Comments and questions encouraged. Anyone who can expand on this, or has their own tricks involving focusing on certain scale degrees please speak up.