Lead Guitar
Guitar Scale Interval Theory Application
All chromatic guitar scale intervals spaced fret by fret on the guitar have 12 half steps. These are finite parts that make up all scales. Music intervals are like a measurement ruler to measure the distance between notes. We measure the distance between notes in half steps instead of inches like a ruler (Ex.1).
Ex.1) 
Instead of 1-12 it’s 1-7 and we have 5 accidental numbers b2, b3, b5, b6, b7 none between 3&4, 7&1 (Ex.2).
Ex.2) 
In music scale theory numbers are used for intervals as an easier way to measure the distance of steps between notes in a music scale or chord. If we count higher than 7 we go into the next octave and 1 starts over again as the 1 in the square of this chromatic scale on the guitar scale fret board (Ex.1). This applies to music scale theory and playing scales on guitar. In chord theory harmony we use interval numbers higher than (7) called compound intervals this will be explained later in future lesson.
Every music scale has scale formula (1, 2, 3, 4, 5, 6, 7 is the Major Scale Ex.4), (1, b3, 4, b6, b7 is the Minor 6 Pentatonic Scale Ex. 5) the bordered numbers. The notes in music are taken from the first 7 letters of the alphabet A-G with 5 accidentals that each have with 2 names (increment A to A# sharps & decrement B to Bb flats) C#-Db, D#-Eb, F#-Gb, G#-Ab. There is no accidental notes between B-C, and E-F (Ex.3). This can be a challenge to learn from our old mental habits of how we use letters in the alphabet also as numbers in counting.
The Guitar Analyzer Diagrams below display visually how to understand intervals. Showing dynamically how the scale formula bordered notes overlay the measuring distance between the notes. This creates an easy way visualize guitar scale shapes to aid guitar players who play by ear.
Ex.1 
Ex.3 
Ex.4 
Ex.5 
The most used blues and rock scales are the Minor Pentatonic Scale and the Major Pentatonic Scale. The Minor Pentatonic Scale contains the root, flattened third, fourth, fifth and flattened seventh (1, b3, 4,5,b7). The major pentatonic scale has five notes – the root note, the second note, the third, fifth and sixth (1, 2, 3, 5, 6 ). In the key of C the minor pentatonic scale is C Eb F G Bb and the major pentatonic scale is C D E G A.
The Major Pentatonic Scale is commonly more commonly used to solo in blues and rock solos. To start learning to master soloing using the Minor Pentatonic Scale. We are going to learn to how to play solos over major, minor and dominant chords.
Let’s take a common blues chord progression using the root, fourth and fifth notes of the scale (I, IV, V). If we are playing a song in the key of C major, the chords are C, F and G major. The minor Pentatonic scales resolves or feels like your playing the right notes, the major pentatonic does not resolve or feel as comfortable until your playing over the V chord G major.
