In previous articles, we covered intervals, chords, keys, scales, and diatonic chords. Now it's time to put all of that knowledge to work. The topic: ear copying — listening to a song you love and recreating it yourself.
🎯 The one trick behind ear copying: find the key
When you see someone effortlessly copy a song by ear, it's tempting to think they were born with better ears. But in reality, much of what they do is theory-based reasoning.
At the center of it all:
Find the key first. Once you know the key, you can make educated guesses about chords and melody.
Because once you know the key:
* The diatonic chords (the chord "team") are revealed → chord candidates narrow to 7
* The scale is revealed → melody and solo notes narrow from 12 to 7
* The tonic, subdominant, and dominant roles are revealed → you can predict what chord comes next
In other words, everything you've learned so far becomes a weapon for ear copying.
👂 In practice — 4 steps to ear copying
Step 1: Listen for the bass notes
You don't need to identify full chords right away. Focus only on the lowest note (bass note).
The method is simple:
1. Loop a section of the song
2. On your guitar, start from the open 6th or 5th string and move up one fret at a time, playing along with the song
3. Find the fret where your note locks in perfectly with the recording
You don't need perfect pitch. Just play along with the song and find the matching note — that's all it takes.
Step 2: Use the bass notes to guess the key
Once you've grabbed a few bass notes, it's time to form a key hypothesis. Two clues help:
Clue 1: Notice where phrases "come home"In the key article, we learned that "a key is the gravitational center of a song." The bass note where the song or a section feels most settled — at the end of a chorus, at the very end of the song — is likely the root of the key.
Take the Beatles' "Let It Be." F appears often in the chord progression, but phrases always land on C to rest. The song ends on C. So the key is C major, not F. F is just a "stop along the way" (the subdominant / midfielder).
Clue 2: Fit your bass notes into a scaleIf your bass notes are C, G, A, F — they all fit inside the C major scale (C D E F G A B). → "The key is probably C major" becomes a reasonable hypothesis.
You don't have to be perfect. Forming a working hypothesis — "probably this key" — is what matters.
🤔 A reminder — a key is not the "answer," it's your interpretation
In the key article, we discussed how "there isn't always one correct key." This idea is just as important when ear copying.
Some people might hear a song as "C major," while others hear it as "A minor." Even professional musicians disagree on this sometimes.
A key isn't a "correct answer" buried inside the song — it's a tool you use for analysis.
"If I assume the key is C major, then this chord progression can be explained like this" — that's the right way to use a key. Set up a hypothesis, see if it explains the music well, and if it doesn't, try a different key.
So don't worry if you can't "find" the key in Step 2. If you're wrong, you'll adjust in Step 4. You're not "discovering" the key — you're choosing one and testing it. This shift in mindset makes ear copying much less stressful.
Step 3: Match chords using the diatonic team
With a key hypothesis in hand, it's time for diatonic chords.
If you're assuming C major, the team is: C, Dm, Em, F, G, Am, Bdim
Match your bass notes from Step 1 to chords from the team:
* Bass is C → try C first
* Bass is A → try Am first
* Bass is F → try F first
* Bass is G → try G first
Your knowledge of relative keys helps here too. If you're torn between "C major or A minor," remember that they use the same seven notes, so the diatonic team is nearly identical either way. You can proceed with confidence.
The key point: try the team members first. Choosing from 7 candidates is far more efficient than guessing from 12.
Step 4: When a chord doesn't fit — revisit the key
Many songs can be fully explained by diatonic chords alone. But real-world music sometimes uses chords from outside the team.
When that happens:
1. Try a substitute chord — chords with similar roles can often swap in (C and Am share a similar role; F and Dm do too)
2. If that doesn't work, revisit your key hypothesis — since a key is an "interpretation," trying a different key is perfectly natural
3. That section might involve a temporary key change (a partial modulation)
The important thing to know: "Chords outside the diatonic set still follow patterns." We'll explore substitute chords in detail in a future article.
🎛️ Experience ear copying with OtoTheory
OtoTheory is not designed to hand you all the answers. The "find the key" part is intentionally left to your own ears. But once you have a key hypothesis, the app becomes a powerful ally.
* Chord Progression Builder: Choose a key and scale, and the diatonic chords appear as your options. Arrange the chords you've picked up by ear and play them back — verify with your ears whether the progression actually matches the song
* Key & Scale Analysis: Enter a chord progression and run the analysis. The app will suggest candidate keys and scales that fit. When you can hear some chords but aren't sure of the key, compare the app's suggestions with your own ear-based hypothesis
* Fretboard display: The notes of your chosen scale light up on the fretboard. When hunting for melody or solo notes, you can see the "safe roads" visually — no need to try all 12 notes blindly
📝 Build your own theory through ear copying
The more you ear-copy, the more you'll accumulate discoveries that no textbook covers.
* "This artist always uses the same kind of chord movement right before the chorus"
* "City pop songs tend to use this combination of chords a lot"
* "This type of ballad almost always ends with this kind of progression"
These observations often don't have official names. But the moment you notice a pattern and can put it into words, it becomes "theory" for you.
In the very first article, we wrote: "Music theory is putting your feelings into words." Theory isn't someone else's textbook answers. It's music expressed in language, in a form you can reproduce — that's what theory is.
Even the patterns found in textbooks started when someone noticed, "Huh, this pattern keeps showing up." Ear copying is precisely the training that sharpens your ability to notice. The more you do it, the bigger your musical toolkit grows.
✅ Summary
The trick to ear copying = find the key. Once you know the key, theory guides the way.
* Step 1: Listen for bass notes (play along with the song and find matching pitches)
* Step 2: Use bass notes to guess the key ("homing note" + "scale fit")
* A key is not the "answer" — it's an interpretation. A tool you set and test
* Step 3: Match chords using the diatonic team (try 7 candidates first)
* Step 4: If chords don't fit, try substitute chords or revisit the key
Ear copying is training that expands your musical vocabulary. Copying many songs is great, and deliberately aiming for a "perfect copy" has real value too. The more you analyze songs you love, the more you'll be able to say "I want that feel in my own music" — and make it happen with theory. When you can put a pattern you've noticed into words, that's already your own theory.
Next up, we'll use the diatonic team to actually build songs — on to Learning Chord Progressions.