James Hetfield, Metallica’s singer, songwriter and of course, guitar player has made reference to his lack of formal knowledge of music theory many a time in interviews and elsewhere. He does mention being taught some theory by the late Cliff Burton, but it’s unlikely he spent time in a class spelling out the relative minor of F major.

Simply put, some great Rock and Heavy Metal guitar players have little or no understanding of music theory.

In order to compensate for their lack of knowledge of music theory these Rock musicians usually have very good aural skills. They are able to “hear” things (either from other musicians or in their minds) and easily figure them out on their guitar.

In the end, it’s the result that counts and, even without ‘knowing music theory’, James Hetfield has proven himself to be one of the world’s best rhythm guitar players and songwriters.

Nonetheless, learning music theory has many benefits for Rock guitar players.

Before I started learning music theory, I was getting all this new information on how to play the guitar, but I simply couldn’t connect the dots.

I knew what a D major and a D minor were, and how to play them on guitar. I could also observe that the minor chords sounded a little ‘sadder’. But I couldn’t understand what was really going on! I didn’t know what a scale was, let alone that the D major chord is built on the first, third and fifth notes of the D major scale.

Things started to make sense to me, when I started learning music theory. I began to understand why certain notes sounded good together, while others sounded more jarring to the ear, the concept of consonance and dissonance.

Eventually, when I started writing my own Rock songs, music theory proved to be even more valuable. It was as if I was presented with a huge palette, illustrating the elements of music, from which I could pick, choose and apply in my songs.

For instance, something I found very valuable was learning how every scale tone can be harmonized with a chord and how the relationship between those chords creates the harmony of the song.

Let’s say you know zero music theory but know how to play a major scale pattern on your guitar.

You start the scale on the note C, then, play the notes D, E, F, G, A, and B until you come back to C again.

If you know the name of the notes on the guitar fretboard, you know that the notes are C,D,E,F,G,A and B just happen they to be there, according to the pattern you have learnt.

Music theory is what tells you why that pattern is as such. That there is a logical reason why, at no point you play an F# or a Bb if you’re playing in the key of C major.

It also tells you that each note is harmonized by a chord which, in the case of the notes in C major would be the C major, D minor, E minor, F major, G major, A minor and B diminished chords.

It tells you what role each chord has in the key it is played in. That for instance, if you play G major followed by C major the progression will sound very conclusive, because G major is the fifth degree of the C major scale, which is referred to as a perfect cadence.

You will learn that in any key, if you play the fifth chord followed by the first, (ex D major followed by G major) it will produce the same conclusive effect.

This may be getting a bit complicated if you don’t know any music theory yet but you shouldn’t let this bother you if this is the case. My goal here is not to teach you how to harmonize scales (which is intermediate music theory), but to give you a glimpse of what music theory is all about and help you take a more informed decision as to whether you pursue its study.

If you’re still undecided whether to go for music theory or not, I believe your answer should depend mostly on these 2 main criteria:

Your goals

If you’re only interested in the money and the chicks, learning songs from guitar tab and joining a cover band may be a shorter way to achieve your goals than learning how it all works.

If you want to become a complete musician, one that is prepared in all musical situations because (among other things) he has the theory to guide him, then, spending a couple of hours each week learning music theory, can take you a long way.

If you want to write songs, then I believe you should start learning music theory right away. You may figure melodies and harmonies out by ear like James Hetfield did, but what’s the point of not making use of a map just because someone else has succeeded without it?

Learn more about setting musical goals in the 5 Steps to a Correct Guitar Practicing Mindset

2. Your musical skills

Rock guitar players who don’t know music theory, may not know that G major followed by C major is a V – I progression, also called a perfect cadence, and that it fits perfectly at the end of a phrase or a song.

But they still use it to end their phrases and songs!

This means that something else has compensated for the lack of music theory knowledge, mainly, good aural skills and hours of practice figuring it out on guitar.

A good ear will discover that V – I progresion is a great way to finish a song and by practice you will figure out how it can be replicated in different keys.

Do you have the ability to learn these skills without the theory to guide you?

Maybe you can. There are many who did.

However, while it does take away some time you could have otherwise spent practicing on your guitar, learning music theory will actually save you a lot of time in the longer run and make the process of learning guitar more enjoyable.

And If you think music theory can’t be fun, read this article to learn what music theory is not. The myths debunked in this article are mostly rooted in experiences people have with music theory taught wrongly.

Though these myths are widespread, Rock guitar players are probably more vulnerable to them than other musicians.

Rock and Roll is rebellion, we don’t need music theory rules!

Yet, when you listen to a Black Sabbath song, no matter how many times those rules are broken, you have to keep in mind there’s a method to that madness.

That when Tony Iommi is breaking those rules and, for instance, accents the most dissonant notes, he’s not defying music theory.

He’s embellishing it.

He’s adding to our collective wealth of knowledge. He found new ways of expressing emotion through dissonance.

Things that have since studied, replicated and experimented on.

Because that’s what music theory does. It keeps evolving as new genres are born and new ideas are tried.

And I see no reason on earth why Rock music shouldn’t be considered as a very valuable part of this amazing phenomena.