Master Guitar Theory: 4-Step System for Rapid Progress

Musical Keys

The definition of a musical key is often thrown around, this often means it can be difficult for guitarists to understand what they are.

Musical keys are a collection of notes that work well together. However, a musical key also contains chords.

We’ve already established that a C major scale has the following notes:

C D E F G A B

And that we can build chords off of those notes:

C major.
D minor.
E minor.
F major.
G major.
A minor.
B diminished.

These notes and chords are what make up the key of ‘C’.

To learn more about guitar keys, go here: Guitar Keys: An Essential Guide

How Do I Find The Key of A Song?

99% of the time, you can tell the key of a song by:

Looking at the first and last chord of a progression.

Here’s an example:

From this we can tell this song is in the key of ‘A’. As the first and last chord are a ‘A’ chord.

What If The First Chord Isn’t The Key?

If you’re not sure on the key of a song, try playing a major scale over that chord progression.

If the scale is in the wrong key, you will know immediately. Experiment with a few different scales until you find one that fits.

Do Musical Keys Stay The Same In Music?

Musical keys change ALL the time. If everything was in the same key, music would become very boring very quickly!

Often, a song has a consistent key, however this can vary when songwriters borrow chords from other keys.

Usually to combat this, if we’re improvising or writing a melody, we would change our melodic notes to fit that particular chord.

However, don’t worry too much about this for now, just accept that it happens. The more you grow to learn about guitar theory, the more you’ll understand about key changes.

Now we understand what keys are, let’s take a look at how scales work in keys.

Scales That Work In The Key

As we found out earlier, the notes C, D, E, F, G, A and B are all notes which create the C major scale.

However, to play a scale in the key of C, we don’t actually need to play all of the notes.

A really great way to condense a scale down, is to play a pentatonic version of that scale.

If you wanted to play in the key of C, you could actually just play a C major pentatonic.

A C major scale, contains:

C D E F G A B

A C major pentatonic contains the notes:

C D E G A

Here’s a C major pentatonic:

guitar theory

Even though the pentatonic scale doesn’t sound as sophisticated as the full C major scale, it would still work over a chord progression in the key of C.

You could also do this with the relative minor scale, we’ve already discovered that A minor, was the relative minor of C major.

The notes in a A minor scale are:

A B C D E F G

The notes in the A minor pentatonic scale are:

A C D E G

Here’s the tab for a A minor pentatonic scale:

guitar theory

Learn this scale here: A Minor Pentatonic Scale: An Essential Guide

This means that, if you knew that a piece of music was in the key of C. You could use any of the following scales over it.

C Major Scale
C Major Pentatonic
A Minor Scale
A Minor Pentatonic

These all contains notes within the key of C, so they would all sound correct.

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How Do I Use Guitar Theory?

Picture the scene, you’ve spent hours and hours learning about guitar theory. But, you get to the band room and you just don’t know how to use it.

It’s great if you can learn guitar theory, however if you don’t know how and where to use it, knowing guitar theory is useless.

Here are 3 quick & easy ways to use guitar theory in a musical situation.

1) Guitar Theory Helps You Improvise Guitar Solos

Understanding guitar theory helps your solo skills. Understanding what guitar scales you can use over a chord progression is half the battle when improvising.

There’s nothing worse than struggling through a solo because you don’t understand understand the theory behind the music.

Knowing guitar theory puts a stop to your solo woes.

To learn how to solo, go here:

guitar theory

2) Guitar Theory Enhances Your Songwriting

Have you ever written a song? Thought it sounded great, but it just needed that finishing touch. An extra chord? A key change to take the song to a new direction? A new melodic idea?

For example, lets say that you’ve written a chord progression which has the chords C and F, but it just needed something a little extra.

You could:

Add in an extra chord from the key of C to spice up the progression.
Use scales to create a new melody over the stop.
Change the key of a song.

Knowing guitar theory takes your songwriting to the next level.

3) Knowing Guitar Theory Enhances Your Musicality

Another great way of using guitar theory, is to add interest to chords and your own strumming patterns.

For example, let’s say we’re playing in the key of C, and the chords we’re using are C, Am and F.

As we know that the key of C, has no sharps or flats, we could actually use any of the open strings to add interest to these chords.

Learning guitar theory accelerates your progress as a guitar player.

However, we’ve only scratched the surface here. There’s a whole world of knowledge underneath the fretboard to discover.

Remember, guitar theory doesn’t turn you into a bad guitarist. It turns you into an excellent one.

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Learn how everything fits together quickly, easily and effectively. We share ninja tips (for instant fun!) but also timeless fundamentals that will deepen your understanding.

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