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The Science of Ear Training

Train your ears to think — and play what you hear.

7min•Updated 2025-11-20•Article 7

1) Ear copying is less mystical when you use theory as a tool

When you try to learn a song by ear, you might:

* Rewind the same part many times

* Hunt around the fretboard

* Land on something "almost right," but still a bit off

Meanwhile, other players seem to:

* Easily copy solos

* Guess the chords in a few tries

* Improvise over new songs on the spot

It's tempting to think:

> "They were born with better ears."

But in practice,

> 🧠 If you use theory as a tool, ear copying isn't as hard as it looks.

You don't have to rely on pure instinct.

2) The core trick: ear copying = "find the key"

Let's state the main idea first:

> 🎯 The core trick of ear copying is: find the key.

Once you know the key, you can:

* Narrow down the chords used in the song

* Predict many of the melody and solo notes

* Make educated guesses instead of random ones

This is the real engine behind ear copying.

Some players do all of this purely by feel.

But if you understand a bit of theory about keys and diatonic chords, then:

> The same process becomes something anyone can learn.

So how do we actually find the key?

Let's turn it into a clear step-by-step method.

3) Four steps: Bass → Key → Diatonic → "Side-trip" chords

We can break ear copying down into four practical steps:

1. Listen for the bass note of each chord and match it on your instrument

2. Use the bass notes to guess the key

3. Once you have a key, test major or minor diatonic chords

4. When something is outside the diatonic set, try substitutions and common side-trip chords —

if too many don't fit, go back and recheck the key

Let's go through them.

① Listen for the bass notes, then find the same note on your guitar

You don't need to name full chords at first.

Start by focusing only on the lowest note.

Ask yourself:

> "For each chord change, what is the bass note?"

And importantly:

> You don't need absolute pitch. You're not trying to recognize C by ear. > You're trying to find the same note on your instrument.

A practical way to do it:

1. Loop a short segment, or pause at the chord change.

2. On your guitar, start from the open 6th or 5th string and move up one fret at a time,

playing together with the song.

3. When one fret suddenly locks in and sounds exactly the same, you've found the bass pitch.

4. Use a tuner or app to check the note name if you're not sure.

So you might end up with something like:

> "First bar feels like 5th string, 3rd fret (C), then 6th string, 5th fret (A), then 4th string, 3rd fret (F)…"

That's already great. Those are your bass-note candidates.

In a way, this is the only part that is truly "pure ear work." Once you can reliably hear and grab the bass notes, most of the remaining transcription can be guided by theory — key, diatonic chords, and side-trip patterns.

② Use the bass notes to guess the key (Let It Be & Twist And Shout)

Next, use those bass notes to work out a likely key.

Here are two practical clues:

#### ✅ Clue 1: Look at where phrases end — the "resting" bass note

* 🎵 In pop/rock, the final bass note of the song

is very often the root of the key (the tonic).

* 🎵 The bass note at the end of a section —

like the end of a verse or the end of a chorus phrase —

is also often the tonic.

Let's check two Beatles examples.

##### Example 1: "Let It Be" (key: C major)

A simplified version of the chorus might look like:

> C → G → Am → F / C → G → F → C

F shows up a lot here, so it's natural to think:

> "Could F be the key instead?"

But if you listen closely:

* F is a member of the C major scale (diatonic), so it's not surprising that it appears.

* The places where the phrase really "comes to rest"

(where the lyrics line feels finished, or the section ends)

tend to land on C in the bass, not on F.

* The very end of the song also resolves to C.

So even though F appears often as a subdominant chord,

the ear feels that:

> The true home is C, > because important phrases and the whole song end there.

That's why we hear the key as C major, not F major.

##### Example 2: "Twist And Shout" (key: D major)

For a non-C example, look at "Twist And Shout."

A rough sketch of the main progression is simply:

> D → G → A (I–IV–V in D major)

Here, you'll notice that:

* The music often moves through G and A,

* But phrases and the song itself keep coming back to D to rest.

So in this song:

> D feels like the final resting place, > the note the music always wants to come back to.

That's why we treat D as the tonic —

G and A are important, but they're "places you visit,"

while D is home.

(Real recordings can include extra decorations and occasional non-diatonic chords, but for now we're focusing only on "where does it come home?")

#### ✅ Clue 2: Fit your bass notes into a scale

Another angle is:

> "Which major or natural minor scale > do my bass notes fit into most neatly?"

Example: if your bass notes are C, G, A, F…

* C major scale: C D E F G A B

* C, G, A, F are all inside this scale

So C major is a strong candidate for the key.

You don't have to be perfect.

> The goal is simply to form a working hypothesis, > like "probably C major" or "probably F major," > and then use diatonic chords and side-trip patterns > to refine that guess.

③ Test major/minor diatonic chords — and remember relative keys

With a key guess in hand, ask:

> "Does this song feel more major-bright or minor-sad overall?"

* If it feels bright → try the major scale's diatonic chords

* If it feels more melancholic → try the natural minor diatonic chords

That's the usual rule of thumb.

But modern music often blurs the line:

* Major-key songs that start on a minor chord and feel emotional

* Minor-key songs with a driving, energetic feel

This is where relative keys become helpful.

Take this pair:

* C major: C D E F G A B

* A natural minor: A B C D E F G

They use exactly the same set of notes —

just starting from different places. These are called relative keys.

So if you're unsure whether a song is "in C major or A minor," you can still:

> Use the same diatonic team of chords and notes, > and you'll mostly land on correct pitches either way.

In OtoTheory's "Find Chords",

C major and A minor will show essentially the same diatonic chords.

So even if you're not confident about major vs minor, it's fine to:

1. Pick one of the two (say, C major).

2. Try its diatonic chords and see how well they match.

3. Adjust your sense of "major vs minor" later.

For example, if we go with C major (and its relative A minor):

* Scale: C D E F G A B

* Diatonic chords: C, Dm, Em, F, G, Am, Bdim

Now map your bass notes:

* Bass C → likely C (sometimes Am or F)

* Bass A → likely Am

* Bass F → likely F

* Bass G → likely G

In other words:

> You use the diatonic chord team of that key > as your first-choice chord list.

④ When chords aren't diatonic, think "substitutions" and "common side-trips"

Real songs don't always stay 100% inside the diatonic set.

They often use non-diatonic chords, borrowed chords, and small modulations.

Two main ideas help here:

1. Substitution chords (代理コード)

* Chords with a similar function that can replace each other

* Example: C and Am can both act like tonic in C major

* Example: F and Dm can both act like subdominant

→ These are mostly inside the diatonic set.

2. Common side-trip chords

* Secondary dominants that briefly tonicize another chord

* Borrowed chords (modal interchange) from a parallel or relative mode

* Short spots where the harmony leans toward another key

You don't need to memorize these terms right now.

What matters is the idea that:

> "Chords not on the diatonic chart still follow patterns in theory."

In practice:

1. First, try the strict diatonic chord that matches the bass.

2. If it doesn't sound right, try a substitution with a similar function (C⇔Am, F⇔Dm, etc.).

3. If many chords still feel wrong, consider that:

* Your key guess might be off, or

* That section might use side-trip chords or a small modulation.

At that point, it's worth going back to check your key and running the steps again.

(We'll dig deeper into secondary dominants and borrowed chords in another article.)

4) How ear copying improves improvising and writing

Summing up, this kind of ear copying quietly gives you:

* A stronger sense of key (thanks to bass + tonic practice)

* Real-world experience with diatonic chord teams

* A growing library of interval-based melody patterns

Which in turn means:

* When you improvise, you naturally know

which parts of the fretboard are likely to fit each chord.

* When you write music, you can say:

"I want that same kind of lift as this chorus, but in my own song."

* When you study your favorite artists,

you can import their ideas as clear musical concepts,

not just vague "vibes."

> Ear copying isn't about becoming a recording machine. > It's about building a musical vocabulary > that your fingers can follow.

5) Using OtoTheory to support your ear copying

OtoTheory is not designed to give you all the answers instantly.

On purpose, it doesn't automatically tell you the key —

that part is your ear's workout.

But once you have a key guess, the app becomes a very powerful helper.

① After you guess the key, go to "Find Chords"

1. Use your ears to form a key guess:

"Maybe C major?" "Maybe A minor?"

2. Open "Find Chords" in OtoTheory.

3. For that key, choose one of the basic scales:

* Major scale, or

* Natural minor scale

4. The app will display:

* The diatonic chords for that key

* The scale tones on the fretboard

Now:

* Use the diatonic chords to test your chord guesses

* Look at any substitution chord suggestions to try functionally similar options

This lets you refine your ear guesses with clear visual feedback.

② Use the scale tones to hunt for melody and solo notes

On the same screen, the fretboard shows the scale tones.

* Try to find the melody and solo notes using only those scale tones first.

* Listen for how most notes fit, and where the song might step outside the scale.

In many songs:

> Most melody and solo notes come from > the main scale of the key.

If things still sound wrong:

* Reconsider your key guess, or

* Try a different scale within the same key

(e.g. pentatonic, modes) and experiment.

③ If you know some chords but not the key, use "Chord Progression"

Sometimes you'll be able to hear:

> "I'm pretty sure the chords are C, G, Am, F…"

…but you're not sure what key and scale that implies.

In that case, use the "Chord Progression" feature in OtoTheory:

1. Enter the chords you've figured out.

2. Tap the analyze button.

3. The app will suggest candidate keys and scales that fit.

You can then compare:

* Your ear-based key guess, and

* OtoTheory's analysis suggestions

to improve your intuition about how chords and keys connect.

6) Recap & a practical next step

* The main trick in ear copying is: find the key first.

* Once you know the key, you can lean on major/minor diatonic chords

instead of guessing randomly.

* When chords fall outside the diatonic set,

you can reach for substitutions and common side-trips,

and if too many don't fit, recheck the key.

* Rather than relying only on instinct,

you use theory as a tool, making ear copying much more manageable.

* OtoTheory supports you by:

* Showing diatonic and substitution chords once you have a key guess

* Letting you see and test scale tones on the fretboard

* Analyzing entered chord progressions to suggest key/scale candidates

A small exercise:

1. Pick one song you like.

2. Try to find only the bass notes by ear, matching them on your guitar.

3. Use those bass notes to guess the key.

4. Open OtoTheory:

* In Find Chords, choose that key and a basic scale

* Test your chord guesses with diatonic and substitution chords

* If you know a few chords but not the key,

enter them in Chord Progression and hit analyze.

Do this for a few songs, and you'll start to feel that:

> Once I find the key, it's almost as if the whole transcription is already done.

Next Steps