How to Use the Chart
The red dots with the big M represents the starting point for playing in the Major scale (if an M dot lands on a G note, you’re playing G major). The small m represents the starting point for playing the minor scale (if a small m lands on E, you’re playing E minor). The black dots are notes that fill in the rest of the scale and they don’t have any particular importance in my chart. The dot that has “3b” inside of it is the note that gives the Blues scale a bluesy sound. In fact, this note is often called the blue note.
(All of the below applies to the Major/minor scale, but can easily be applied to the Pentatonic and Blues without issues.)
Let’s say that you want to play the A major scale using the left shape. To play this, you slide the scale around until one of the big “M” dots land on a A note. In the left shape, the big M is on the G string, 2nd fret. Coincidentally, this is where you’re going to play this shape on the fretboard. If that one note all the way to the left in this shape is on the first fret, then your big M lands on A, and you’re playing the A major scale.
Now that you’re playing the A major scale, try noodling along with a song that’s in the key of A. “Fake Plastic Trees” by Radiohead is in A, so is “Help”, by The Beatles. If you good off in those scales while listening to these songs, it will sound more or less fine. Slide everything up or down a fret and you’ll hear just how bad it can be to play along in the wrong key. In order to play in a different key, just slide your shape around on the fretboard until one of the big M’s lands on the major key you want, or one of the little m’s for the minor key you want. This will require you to know some notes on the fretboard, otherwise you’ll never know what key you’re playing in. Here’s a picture of the notes on the fretboard that I pulled up after a few seconds on google.
If you wanted to you could only learn this shape and noodle around in this position forever but if you want to play A Major further up the neck then you’re going to have to play a different shape. Or rather, add another shape to this one. That’s where you use the middle shape in my chart. It overlaps with the other two, so you just tack it towards the end of shape number 1 and presto: you have extended your A major scale by 4 frets. To go even further, repeat with shape 3.