The Ultimate Music Theory Guide

In this section you'll find a list of terms that are integral to understanding the rest of the content in this guide. You're most likely familiar with the majority of them but I'd recommend having a quick skim through, just in case!

A fundamental part of scales and chords, an interval is the distance between 2 notes and consists of 2 descriptors: the type (minor, major, perfect, flat or sharp) and the numerical value (unison, 2nd, 3rd, 4th, 5th, 6th, 7th or octave).

Training your ability to recognize intervals will vastly improve the speed at which you can learn songs by ear and help translate the music you hear in your head onto your instrument.

Here's a list of all intervals you're likely to encounter...

A key is the predominant group of notes that form the harmonic foundation of a piece of music. This group of notes are nearly always all from one particular scale, and it's this that we derive the key from.

But how do we work out what key a song is in?

Unlike Classical and Jazz music that has formal written notation with key signatures included, Metal musicians often don't have that luxury so it's down to us to work out the key ourselves!

In 99% of cases it's incredibly simple as the vast majority of songs start with the "home" chord - so this is the first place to look.

Go to the first bar of the song and find the "strong" note (this could either be the note the song starts with or that appears most commonly throughout) and then keep playing it over the song.

Even as the chords/riffs change as the song progresses, if you keep playing the home note it should still sound fine; as you'll most likely find that the chords/riffs keep resolving back to your home note.

If your ears aren't so well trained then there's gonna be a lot of trial and error involved with working out keys; but as your listening skills improve I guarantee you'll be able to do it quicker and quicker.

Also, remember that keys can only ever be major or minor! So after you're confident you've found the home note, all that's left to do is confirm whether it's in major or minor (though let's be real, in Metal it's gonna be minor 90% of the time).

A great way to reaffirm your choice is to do a bit of simple improv over the top of the song. For example, if you think the song is in E minor, then try jamming some licks in the key of E minor over the top and see if it sounds right or not.

There will sometimes, however, be cases where it's not entirely obvious what the key is and a bit of assumption is necessary.

Rhythm is an often-overlooked aspect of music theory that guitarists don't seem to spend anywhere near enough time on.

While it's by no means necessary to become a rhythmic expert, it's still essential that you have a decent understanding of the fundamentals, such as: note values, note value modifiers and time signatures.

At the most fundamental level a chord is 3 or more pitches played simultaneously. At minimum, these consist of a root, 3rd and 5th (with the notes that these intervals represent being derived from a scale).

For example, to construct a C major chord you simply take the root (C), 3rd (E) and 5th (G) of the C major scale and play them in unison.

Similarly, to construct an F minor chord you take the root (F), 3rd (Ab) and 5th (C) of the F minor scale and play them in unison.

Another name for these fundamental 3 note chords which you may have heard is a "triad". So no matter what kind of C major chord you play (open chord, barre chord, whatever), it will always just be a combination of C, E and G notes in various combinations.

Similarly with F minor, it will always just be a combination of F, Ab and C notes in various combinations.

Of course there are many other types of chords besides just major and minor - the possibilities when it comes to chord construction are literally limitless! Though, as was the case with scales, as a Metal player it's only really necessary to put time into learning the most commonly used ones.

Here's a list of all the chords I suggest learning:

Scales are the tonal basis of pretty much all music. Whether you're riffing, soloing or strumming chords; you're interacting with scales somehow. Therefore it's super important you understand how they work!

At its most basic definition, a scale is an ordered sequence of notes that form a progression between one note and its octave, separated by predefined intervals. The type and order of these intervals is what determines which scale you're dealing with.

It's obviously not feasible (or productive) to learn every single scale in existence, and as a Metal player you really only need to learn 3 essential scales to make decent progress with your playing: the minor scale, major scale and minor pentatonic scale. Most other scales and modes are just slight variations on these—so learning these 3 is already doing half the work!

Even though it's such a musically-diverse genre, the vast majority of Metal really only uses a handful of scales. Once you have a decent grasp on the core and pentatonic scales, here are the essential harmonic, melodic and exotic scales that are widely used in Rock and Metal.

A mode is basically the same thing as a scale... but slightly different!

A scale is an ordered set of notes with a clearly defined start and end point. But what happens if you mess around with these start and end points?

For example, we know that the notes of the C major scale are...

But what if we played the same scale starting from D instead?

Is it still the C major scale? Well, yes... but also no!

Even though the notes therein stay exactly the same, making a scale start from a different home note completely changes its context. This is where modes come into play.

There's a lot of confusion and mystique surrounding the modes; largely because most guitarists approach learning them the wrong way.

What people often don't realize about modes is that they're just as much to do with chords as they are to do with scales.

For example, if you play the previous example (D > E > F > G > A > B > C > D) in isolation then it doesn't sound like a fancy, exotic mode - it just sounds exactly the same as the C major scale. But if you play it over a G major chord... woah! It suddenly sounds way cooler.

It's not until you play a mode over the "correct" chords that it suddenly comes to life and sounds like it should. When it comes to modes: context is everything!

I highly recommend following my comprehensive 4 part course on modes in order to fully understand how they work and how to apply them, but in the meantime here's a complete breakdown of how modal colour works and each of the modes.