Struggling To Play Guitar By Ear? Learn Music Theory. Here’s Why.

Guitar and Headphones

Learning to play guitar by ear can be a frustrating process. There is no magic pill, and it definitely takes some time and dedication to acquire the ability. Luckily, there is one solid fundamental skill you can work on to make the process a lot easier, and that’s learning Music Theory.

A solid understanding of Music Theory principals helps when learning to play guitar by ear because it gives the player a much deeper understanding of what they are hearing. It makes songs and chord progressions more predictable and much less confusing.

The investment of time you put into working on improving your music theory skills is time well spent that you will never regret. It will help to make the experience much more enjoyable and manageable the next time you sit down and try to work out a song, progression, or melody by ear. Let’s take at look why this is true…

Songs are more predictable than you may think. One chord can reveal all the others.

If you can figure out what key signature a song is in when you are attempting to learn it by ear, the process is going to be so much easier!

What is a key signature?

In basic terms, a key signature (or simply “the key”) refers to a core chord or note that the song revolves around. Many times (not always) this is the first and last chord that is played in the song. Next time you attempt to work out a song by ear, fast-forward to the very end of the song and try to discern what the last note or chord being played is.

Most chord progressions build tension in the listener’s ears and force the need for the song to resolve to a particular chord or note. It takes a little practice to get a feel for exactly what this sounds like.

We’ll use the song “Peaceful Easy Feeling” by the Eagles as an example for this. Grab your guitar (or any instrument for that matter) and try to figure out what note this song ends (or resolves) on. Don’t worry, if you’re struggling to get it, I will reveal the answer below.

So, the best thing to do is to listen to the entire song so that the chords that are being played really get burned into your memory as you are listening. If you don’t want to listen to the entire song, skip to the 3:55 minute mark and listen until the last chord of the song is played at 4:09 minute mark.

What is the last Chord?

Listen to that last chord at 4:09 and try to hum the note in your head. Now, do it one more time (repetition is essential). Maybe try to lightly sing the note out loud. It doesn’t have to sound like Michael Jackson, just try and match one of the notes being played.

Now pluck around on your instrument (make sure that the instrument is tuned properly) and see what note you find that sounds like the note you are humming. Which note can you find that sounds best?

Any luck? Need a hint? It’s one of these notes

  • D
  • E
  • G
  • C

Which note out of those sounds like it’s the right note?

If you guessed E, you are totally correct! This song is in the key of E because you can clearly hear that the song resolves on an E chord. Notice when the song ends, it really sounds completed and like it was ended on the proper chord. It just sounds right.

Now, if you didn’t guess the note E initially, there are two other notes that would have been good guesses. Those are the notes B and G#. The reason these notes are logical guesses is because they are actually found within an E major chord. An E major chord is made by playing the notes E, B, and G# together at the same time (or in harmony).

If you thought one of these notes was the last chord of the song, you were partially right so good on you for being so close. For those of you who guessed something else, don’t beat yourself up. Playing by ear is a learned skill that takes time. The process takes practice and will get easier and easier the more you work at it. Don’t give up!

Now, what does this have to do with the song being predictable through Music Theory, as I stated in the title of the title of this section? Great question.

With a good foundation of music theory understanding, you will know that every key signature has a built in set of chords that you can use together in a piece of music to make beautiful sounding chord progressions. For instance, the key of E Major contains these chords:

  • E major
  • F# minor
  • G# minor
  • A Major
  • B major (or B7)
  • C# Minor
  • D# diminished

Look up the chords to the song “Peaceful Easy Feeling” on Google. You will notice that many of these chords are played at different points in the song (some may be variations of these chords). So, if you were learning this song by ear and knew some music theory, you would already have a predictable set of chords that are likely to be played in the song because we know it was recorded in the key of E Major.

How awesome is that? You don’t have to just blind guess anymore, there’s actually some rhyme-and-reason to all this musical madness.

Here is an article I wrote on the basics of music theory that you can use as a reference to help you progress your playing and musical knowledge. Check it out, I think you will find it very helpful. I try to describe the concepts as simply as possible.

Understanding Music Theory helps you recognize the way different intervals sound.

The ability to instantly know exactly what interval is being played is very helpful when transcribing a piece of music by ear. An interval is simply the distance between two notes. A good grasp of theory will help you develop an understanding of the way these intervals sound and help you to recognize them instantly when listening to a song.

Without going into too much detail about how music theory works, I’ll explain how you might encounter these intervals in a song.

Let’s use the key of G major for this example. G major is a very common key for songs written and played on the guitar. The notes found within the G major scale are:

  • G
  • A
  • B
  • C
  • D
  • E
  • F#

Using these notes we can build out the chords found within the key of G major (or G major scale). The chords found within this scale are as follows:

  • G major
  • A minor
  • B minor
  • C major
  • D major
  • E minor
  • F# diminished

Often times you will hear musicians reference the chords in a scale based on the position they fall within that scale (sometimes using roman numerals). For instance, in our chords listed above, G major is the 1st chord found within the scale or the I chord (I meaning one). A minor is the 2nd chord found within the scale or the ii chord (two chord). Here’s a quick chart:

ChordPostionRoman Numeral
G major1stI
A minor2ndii
B minor3rdiii
C major4thIV
D major5thV
E minor6thvi
F# dim7thVII
Chords, Positions, Numerals in G major

*Note that the minor chord roman numerals are written in lower case to distinguish that they are minor.

Ok, now we know the chords and their positions in the key of G major. So what? How does that help us learn a song by ear? Well, when a chord from the scale is played and then the progression changes to another chord, there is a measurable/recognizable interval change that has just occurred.

Let’s use a very common interval change as an example. We will change from the I chord (G major) to the IV chord (C major). Commonly you will see this change written in roman numerals like so, I – IV.

Now, grab your guitar and strum a G major chord 4 times. Get the sound of that chord burned into your head. Next, with that sound still in your head make the I-IV interval change by strumming the C major chord 4 times. Do this a few times over. Strum G major a few times and then strum C major a few times. Listen to how these chords sound in relation to each other.

This helps when learning a song by ear because regardless of what key signature the song is written in, a change from the I chord to the IV chord will always have the same interval relationship and create the same interval sound. Try some of these, they are all I – IV intervals.

  • E major to A major
  • C major to F major
  • D major to G major
  • A major to D major

The more you practice this type of exercise, the more you will be able to recognize this interval within a piece of music that you are transcribing by ear.

Now, let’s take this a step further. We’ll play a chord progression in two different keys. You’ll be able to hear that the interval sounds the same even when using different chords.

Our chord progression will be a I – vi – IV – V or a (1st – 6th – 4th – 5th) interval progression. Using G major our chords will be:

G major – E minor – C major – D major

So let’s play it. Strum each chord slowly 4 times then change to the next chord. After strumming the V chord 4 times return to the I chord for one final strum. You should hear the progression resolve back to the key signature of G major. Like this:

  • G major (4 strums)
  • E minor (4 strums)
  • C major (4 strums)
  • D major (4 strums)
  • G major (1 strum)

You may recognize the way these chords sound in relation to each other, as this is a very popular chord progression in modern music.

Now, let’s try the same progression using a different key signature. The key of E major. Here is our list of our E major chords from the “Peaceful Easy Feeling” example from above.

  • E major
  • F# minor
  • G# minor
  • A Major
  • B major (or B7)
  • C# Minor
  • D# diminished

So, what are the chords we will be using to play the I – vi – IV – V chord progression in the key of E major? They are:

E major – C# minor – A major – B major

So play this and see if you can hear how similar it sounds to when we played it in G major.

  • E major (4 strums)
  • C# minor (4 strums)
  • A major (4 strums)
  • B major (4 strums)
  • E major (1 strum)

Can you hear it? Crazy right?

Here’s another song in the key of E with the same chords but in a different interval pattern. It uses the chords:

E major – C# minor – A major – B major

…But in a different pattern. Try and figure out by ear what the pattern is (just use the opening part of the song for this exercise). Grab a sheet of paper and write down the chords in the correct order and then write down the progression using roman numerals.

What did you come up with??

If you guessed:

E majorB majorC# minorA major

Then you’re totally correct!

This song uses a I – V – vi – IV progression. Not so complicated huh? See if you can utilize these concepts the next time you are sitting down with your guitar and learning a song by ear. Try and think of the chords in relation to each other opposed to just being chords that were randomly selected by the song writer.

If this whole scale, chord, progression jargon was confusing, I suggest you check out that music theory basics article I wrote. It has a much deeper explanation of how all this works.

Different chord variations will be less confusing.

Music theory knowledge will help you to understand why different chord variations sound good within a given chord progression. For instance, let’s use our E major chords from above. Commonly guitarists will use chord variations to lead a chord to want to resolve to another chord.

While playing chords in the key of E major, a song writer could do something like this to control the flow of how a song wants to move. Let’s say that the guitarist has played an A major chord and wants to take the song back to the root chord of E major. He could simply alter the A major chord slightly to cause tension in the listener’s ears and cause a craving for the chord to resolve.

For example, the notes that make up an A major chord are A, C#, and E. If he played an A major chord and then moved to an Asus2 he could add some tension to the progression. Why would this happen?

An Asus2 chord is made of of the notes A, B, and E. So, essentially the C# note of the A major chord is dropped two notes lower to a B note. Take a look at the E major scale.

  • E
  • F#
  • G#
  • A
  • B
  • C#
  • D#

With some music theory understanding you would understand that when the 5th note or chord of a scale is played, it causes tension for the listener (also know as a cadence) that forces the song to want to resolve back to the root chord of the key. In this case, it would be E major.

So, in our A major to Asus2 chord variation from above, the song writer is forcing the movement of the chords through the notes that he chooses to play.

Your music theory knowledge will greatly help your ability to be able to hear and understand these types of variations that occur in a song. You will be able to pick up on these subtle changes a lot easier if you have some understanding as to why the chord variation was chosen in any particular situation.

There is more to writing great chord progressions than it just “sounds cool”.


Although we haven’t covered every reason why having a grasp on music theory will help you when playing guitar by ear, I have tried to drive in some points that may give you a little extra boost to learn it. If you put the work in to expand your musical knowledge, you be repaid in great dividends when you sit down and transcribe a song by ear.

Recent Content