This post contains affiliate links, meaning, if you click through and make a purchase, I may earn a commission. This is at no additional cost to you. Learn more.
Learning music theory is less common with guitar than it is with other instruments. It’s absolutely possible for guitarists to reach extremely advanced technical ability levels while knowing next to nothing about music theory. However, for a working musician it’s an essential skill. Transcribing your songs, using music software, teaching, professional composing, or directing the Philharmonic orchestra at the rehearsals for your Death-Metal-Band-Plus-Live-Orchestra-Tour are all nearly impossible tasks without at least a basic working knowledge of music theory for guitar.
So let’s start at the very beginning.
The Notes and Chromatic Scale
First things first: we need some notes! In Western music there are 12 notes in existence that make up “the chromatic scale.” They are:
C C#/Db D D#/Eb E F F#/Gb G G#/Ab A A#/Bb B
The Chromatic Sequence of Notes:
In these note names the # means “sharp” and the b means “flat.” You may have previously heard note or chord names like “F sharp” and “B flat.” This is why.
So, for example, the note between C and D is C#/Db (C Sharp or D flat). This is just one note, with two possible names. Why you’d opt for one of the names in particular comes much later. For now, either name is fine.
These two possible names for the same note are what we call enharmonic equivalents. There is no difference in pitch/sound, or position on the fretboard. C# and Db are the exact same note. It’s just like ordering “chips” in a British restaurant and “fries” in an American restaurant. Different word, but you still end up with the same thing!
The exceptions: You may’ve noticed that E goes straight to F, and B goes straight to C. There is no E#/Fb or B#/Cb.
Imagine the keys on a piano keyboard (or better still, go and play one). These enharmonic equivalents–sharps or flats–are all the black keys on the keyboard. You’ll also see that indeed we go straight from E to F, and B to C, with nothing in between.
TIP: Relating things back to the piano (or keyboard) is extremely useful when learning music theory. If you don’t have one, see if you can get your hands on one from a friend, relative, or dusty attic. Or, you can pick up a basic new one pretty cheaply these days.
Semitones and Tones
There are two terms you need to learn now, if you don’t already know them. They are “semitone” and “tone.”
Semitone
This is a distance of one degree of the chromatic scale. Examples would be from C to C#/Db, or from E to F. In practical terms, this is a movement of one fret along the fretboard, or one key on the piano.
Tone
This is a distance of two degrees of the chromatic scale e.g. from C to D or from E to F#. In practical terms, this is a movement of two frets along the fretboard, or two keys on the piano.
If you ever struggle to remember which is which, the clue is in the prefix “semi” which means “half.” A semitone (1 step) is half of a tone (2 steps).
Still with me?
The Major Scale
The Major scale (the Do-Re-Mi scale) is the foundation of modern Western music. It is constructed from a starting note using a series of moves or steps, all of which are either a semitone or a tone.
Example: Constructing the C Major Scale
- We start with the note of C (our “root note” or “tonic”).
- From there, the formula (where T = tone and ST = semitone) is: T T ST T T T ST
- C (tone) D (tone) E (semitone) F (tone) G (tone) A (tone) B (semitone – back to C)
So the C Major scale is: C D E F G A B
The key point here is that this is a formula. This is not specific to the C Major scale–this is how you construct any Major scale.
Example: Constructing the D Major Scale
- We start with the note of D (our “root note” or “tonic”).
- Again, use the Major scale formula: T T ST T T T ST
- D (tone) E (tone) F# (semitone) G (tone) A (tone) B (tone) C# (semitone – back to D)
So the D Major scale is: D E F# G A B C#
Different notes, but the same process, which you can use to construct any Major scale.
Exercise: Give it a Try!
Now that you know the formula, give it a try. Use what you’ve learned to build two Major scales yourself. Try to write out the notes in the E Major Scale and the Bb Major scale.
Hints:
- When building your E Major scale, use only the “sharps” when you get to a note that has an enharmonic equivalent.
- When building your Bb Major scale, use only the “flats” when you get to a note that has an enharmonic equivalent.
Once you’re finished, check your work here:
Show Answer - E Major Scale
E Major Scale: E F# G# A B C# D#
Show Answer - Bb Major Scale
Bb Major Scale: Bb C D Eb F G A
The Minor Scale
The equally important second component of music theory is the minor scale. Simply put, music based on minor scales is often described as sounding “sadder” than music based on Major scales. While this description is quite general and basic, it sums the situation up pretty well at a surface level.
Here’s the formula for constructing a minor scale: T ST T T ST T T
So, the A minor scale would be:
A (tone) B (semitone) C (tone) D (tone) E (semitone) F (tone) G (tone – back to A)
Again, this is entirely formulaic, so although an E minor scale will contain different notes than this, and the G minor scale different notes again, they are all formed in the same way: by taking the tonic/root note then moving in tones and semitones to form the scale.
Exercise: Give it a Try!
Now that you now the formula, give it a try. Use what you’ve learned to build two minor scales yourself. Try to write out the notes in the B minor scale and the E minor scale.
Hint: When building your minor scales, use only the “sharps” when you get to a note that has an enharmonic equivalent.
Once you’re finished, you can check your work here:
Show Answer - B minor Scale
B minor Scale: B C# D E F# G A
Show Answer - E minor Scale
E minor Scale: E F# G A B C D
Chords and Keys
What’s the difference between a scale and a key?
As you just learned, a scale is a sequence of notes formed using a recognized formula.
A key is a sequence of chords formed from a scale.
Keys
A “key” is a group of 7 chords that are related to each other and deemed to “go well together.” These 7 chords are formed from the 7 notes in a scale, by assigning a chord type to each step of the scale. This sounds complicated, but is very simple. Let’s review some examples to help you make sense of it.
Major Key Formula
In a key of chords, the Major key formula will always be as follows:
Chord 1 = Major
Chord 2 = minor
Chord 3 = minor
Chord 4 = Major
Chord 5 = Major
Chord 6 = minor
Chord 7 = diminished
So the key of C Major (the 7 chords ‘belonging to’ the C Major scale) contains the following chords:
C Major
D minor
E minor
F Major
G Major
A minor
B diminished
For now, you don’t need to worry about why these chords are Major, minor, or diminished. Those are topics for a later, slightly more advanced music theory course. However, the answers are out there and easy to find if you’re curious and would like to explore further on your own
Additionally, you’ll notice that we capitalize the “M” in Major, but a lower-case “m” for minor and a lowercase “d” for diminished. This is done on purpose, but you don’t need to worry about that right now.
TIP: Do make sure you know at least one way to play a diminished chord so that, for the time being, you can practice it and use it in your playing.
Remember: This is a formula and the formula stays the same in all Major keys.
Exercise: Give it a Try!
Use everything you’ve learned so far to find all the chords in the key of E Major. You don’t need to be able to actually play all these chords yet–you can do that later if you’d like. For now, we’re just finding all the chords “on paper.”
Follow these steps:
- First, write out all the notes in the chromatic sequence of notes (Hint: refer back to “The Notes and Chromatic Scale” section above)
- Next, start with “E” and extract all 7 notes of an E Major scale (Hint: use the Major scale formula you learned in “The Major Scale” section above)
- Lastly, assign chord types (Major, minor, or diminished) to each step of the scale.
Once you’re finished, you can check your work here:
Show Answer - Chords in the Key of E Major
Chords in the Key of E Major:
E Major
F# minor
G# minor
A Major
B Major
C# minor
D# diminished
Once you have all the chords in the key of E Major, guess what? You now have all the chords you need to write a song in that key! If you know how to play these chords, go ahead and give them a try. Practice playing some of the chords together and see how they sound (some will sound better together than others).
Minor Key Formula
In a minor key the formula is:
Chord 1 = minor
Chord 2 = diminished
Chord 3 = Major
Chord 4 = minor
Chord 5 = minor
Chord 6 = Major
Chord 7 = Major
So the key of A minor (the 7 chords ‘belonging to’ the A minor scale) contains the following chords:
A minor
B diminished
C Major
D minor
E minor
F Major
G Major
Remember: This is a formula and is the same in all minor keys.
Exercise: Give it a Try!
Again, use what you’ve learned so far to find all the chords in the key of F# minor.
Follow these steps:
- First, write out all the notes in the chromatic sequence of notes (Hint: refer back to “The Notes and Chromatic Scale” section above)
- Next, start with “F#” and extract all 7 notes of an F# minor scale (Hint: use the minor scale formula you learned in “The Minor Scale” section above)
- Lastly, assign chord types (Major, minor, or diminished) to each step of the scale.
Once you’re finished, you can check your work here:
Show Answer - Chords in the Key of F# minor
Chords in the Key of F# minor:
F# minor
G# diminished
A Major
B minor
C# minor
D Major
E Major
Summary of Key Points
- # = Sharp
- b = flat
- C# and Db are alternate names for the same note, or “enharmonic equivalents”
- A semitone is one step/fret/piano key
- A tone is two steps/frets/piano keys
- Major scale formula: T T ST T T T ST
- Minor scale formula: T ST T T ST T T
- Chords in a Major key: Major – minor – minor – Major – Major – minor – diminished
- Chords in a minor key: minor – diminished – Major – minor – minor – Major – Major
Final Thoughts
So, there we go! That’s the end of The Very Basics of Music Theory for Guitarists. Starting with all the notes in existence, to theory-based songwriting via tones, semitones, scales and keys. One very important thing to remember is that music theory is a HUGE subject full of details, examples, rules and exceptions. It is absolutely OK to go away from this post having only understood 65% of it. Learning music theory for guitar is an ongoing process of gradually widening your knowledge, and learning and re-learning things as they continue to come up. The best thing you can do is to take that 65%, and go and apply it now!
Good Luck!
If you have any questions, please let me know down in the comments below.
Further Reading: Recommended Books on Music Theory for Guitarists
Have a desire to learn more about music theory for guitar? Here are 4 good books that’ll help you take your music theory knowledge to the next level:
Written by Alex Bruce
Guest Contributor
Alex is a Guitarist, Guitar Teacher, and Writer with 15 years experience. He runs Bruce Music, a guitar and piano school based in London, UK. They are a community of young, active working musicians who visit students all over the city to provide expert guitar and piano tuition.
What a gem this man is!
Such a clear explanation of what appeared to be such a confusing pile of arbitrariness.
I feel inspired to learn more from this solid base.
THANK YOU!
That’s great to hear Tim! I’m so glad to know this article is helping people get their feet wet with music theory.
This is really nicely laid out, and the examples and exercises are useful. Thanks!
Thanks Rob! I’m glad you found this article useful.
Awesome explanation! I’ve been struggling to understand the relationships of keys, scales, and chords, and this article gave me that “aha moment”.
Hi July! I’m so glad to hear that you found this post useful.
Thank you guitaranswerguy for giving me wonderful information about music theory
You’re welcome Rohit! I’m glad to hear that you found the information useful.
Under, “MAJOR KEY FORMULA”, you said: “For now, you don’t need to worry about why these chords are Major, minor, or diminished. Those are topics for a later, slightly more advanced music theory course.”
But I AM worried, about why these chords are such (M m m M M m dim)… So where do I go to find out why? My search of the internet is fail.
Thanks.
Thanks! Really appreciated this post. Overwhelming amount of guitar content online, so its refreshing to see something explaining from the ground up.
Clear and concise information and a well-designed, uncluttered website. Subscribed! Thank-you!!
Wow, thanks Michelle! Glad to have you aboard. If you ever have any questions, feel free to reach out and contact me anytime.
Your article has a really good information and awesome tips. Please keep up the good work. Your information helps me a lot to increase my guitar skills. Photos are well arranged.
Thank You….
Thanks Yash! Knowing that this stuff is actually helping people is what keeps me going.
This one page put a lot of the basic information into context. The information was so well presented and easy to follow. I wish there were more exercises like the one’s above. Thank you for this information, it really helps adult learners like myself make sense of the basics of music theory!
You’re welcome Malora. I’m glad you found this helpful!
Hi,
I was doing a search on guitar theory, mostly how to figure out how players like steely dan (Walter Becker and Curington, not sure of his spelling) put in all these sharps and flats and never sound out of key in their solos. I know scales and a lot of theory but I just can’t get there!
Great site!
Vinny
In the last exercise to find all the chords in the key of F# minor, you wrote in the second step to use the Major scale formula in “The Minor Scale” section to extract the notes of an F# minor scale and I wondered if that was incorrect. Should we not use the minor scale formula, instead?
You’re right Robert, that was indeed a type-o and I’ve corrected it. Sorry for any confusion that may have caused, and thanks for catching it!
A very well explained and easy way to begin theory. Job well done. And where were you 44 yrs ago when first I began this road. :=}
Steve
Back then, the only guitarists that learned music theory (and sightreading, for that matter) were Classical guitarists who either studied with a prominent private instructor and/or studied music at the university level. After Classical guitarists, Jazz guitarists were probably the most well-versed in theory, but it usually wasn’t something they consciously TRIED to learn. They simply HAD to know the fundamentals to play over all those changes. Rock and country musicians? Not so much 😀
Glad I am starting now … Well 4 years ago. I am ready for some music theory. Thanks for some basics.
Gday, good job on the basics that can be applied right away, I teach theory and composition to guitarists and that was a really good intro guys, well done!
Thanks Steve, appreciate the feedback!
Well Done!
Break it down into sections and you have a great beginner’s coarse!
I might use this. Forward it to a couple of people online that I’m helping… 😉
Thanks Luke! Glad you liked it and found it useful.