How to Figure Out the Key of a Song by Ear on Ukulele

Learning to figure out the key of a song on the ukulele is an ear training challenge. It’s a very important skill, but can be frustrating at first.

To help you get started, here are some pointers to focus your efforts.

First of all, why would you want to know the key?

If you’re playing ukulele by ear, it’s relatively simple to figure out the melody to a song. But figuring out the chords to a song by ear, without any kind of guidepost can be very tedious.

Learning to figure out the musical key first can significantly narrow down the chord possibilities. Instead of randomly trying dozens of chords, when you know the key, you can jump straight to the three to six chords that are most likely to accompany the melody.

The “Cog” Layout

The easiest way for most people to figure out the key of a song is to discover which notes sound right. Then you can figure out which key signature includes those notes.

There are 12 chromatic musical notes in Western music:

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C C#/Db D D#/Eb E F F#/Gb G G#/Ab A A#/Bb B
The chromatic scale can be started from any note. It’s basically every fret on every string of your ukulele.

A key – essentially the notes of a major scale – is made up of a combination of seven of those chromatic notes.

The notes in a major key always follow the same pattern:

W W H W W W H

(W = whole step/two frets, H = half step/one fret)

By aligning this pattern with the 12 note chromatic scale, you can see the notes of a major scale, and therefore the key.

There is a key based off of each note in the chromatic scale for 12 total key signatures.

Here, the pattern is starting on a C note (red arrow). From arrow to arrow you can see how the W W H W W W H pattern creates a major scale from the chromatic scale (shown on the teal circle):

chromatic scale with c major key shown with arrows infographic

Red to pink: whole step, pink to purple: whole step, purple to blue: half step, blue to cyan: whole step, cyan to green: whole step, green to yellow: whole step, yellow back to red: half step

If we rotate the arrows clockwise by one note, we’ll be starting on (and thus playing) a C# – or Db – note. (It’s the same sound, but you can call it by either its sharp or flat name.)

The arrows are still the same distance from each other. All that’s changed is their rotation around the chromatic scale:

chromatic scale with c#/db major key shown with arrows infographic

Each of those arrow variations end up being a major scale, depending on the note you start on. On the first chart, the arrows point out the notes in a C major scale. In the second, C#/Db major.

Here are the two scales back to back for reference. They’re just one “click” of the dial different:

rotating c major scale to c#/db major scale around a chromatic scale

When you’re figuring out a key by ear, you’re trying to find the combination of notes that rotate the dial to fit what I call the “cog” layout.

The good news is that you don’t have to start your search from the root note – the starting note. You can locate any of the notes around the dial in any order.

Here’s the key of A major. Same arrow layout, different amount of rotation:

chromatic scale with a major key shown with arrows infographic
Once you become really comfortable finding ukulele keys by ear, you’ll only need to hear a couple of notes in order to know the key. You’ll eliminate large chunks of the cog layout with each note your play.

To learn more about the hows and whys of this pattern, check out:

street theory music theory video workshop cover thumbnail
▶️ Video Course

Understand the basics of practical music theory for the ukulele.

Finding the Notes by Ear

Looking at these charts and studying the arrow layout, you might realize something profound:

You’re only ever one fret away from a right note!

If you play a “wrong” note, slide your finger up or down in either direction and you’ll be on a note that’s part of the key you’re searching for!

Here’s a great overview video about this concept:

With this bit of information in mind, you can listen to a song and start plucking random notes.

Here’s a classic, long song (so you don’t have to press rewind as much!) by Gabby Pahinui:

Put it going and start picking random places on your ukulele. For ease of use, playing along the A-string will provide easy access when it comes time to figure out what notes fit.

Listen to each note and assess:

  • Does it “fit” and sound musical?
  • Does it sound sour and dissonant?

If it sounds musical, figure out the name of the note with a fretboard chart or by counting up from the open string. Make a mark on your ukulele key bingo card!

If it sounds sour, try moving up or down a fret to see if it brings the note to a happier sound.

Keep in mind that over certain chords and against certain parts of the melody, even “right” notes can sound dissonant.

If you’re not sure, pick the note repeatedly until there is a chord change. Or move up or down a fret. It’s much easier to hear if a note is in the key when you move from one place to the next (i.e. better>worse or worse>better).

The more notes you find that sound like they fit, the closer you will be to identifying the key.

Some notes may be harder to find consensus on than others. Figuring out the key of a song by ear is a challenging task and sometimes you might not be sure if something sounds right or not.

In general, the longer you’ve been playing and using your ears musically, the easier this is. If you’re super tone deaf it might be frustrating, but my experience is that most people can tell the different if given practice.

To confirm or deny your suspicion of being tone deaf, there are a few fun quizzes you can take. (Remember, you can always improve, even if you really bomb at first!)

Assuming you can find seven notes that fit the sound of the song (and five notes that don’t), you should be playing the major scale of the key.

Determining the Key

As you collect notes that fit on your ukulele key bingo card, you can start comparing them against the notes in common keys. You can sort the possibilities with a chart like the one below or figure it out in your head/on your uke.

Here are all 12 keys, in rough order of use. More common ones first:

C  D  E  F  G  A  B  C
F  G  A  Bb C  D  E  F
G  A  B  C  D  E  F# G
A  B  C# D  E  F# G# A
D  E  F# G  A  B  C# D
E  F# G# A  B  C# D# E
Bb C  D  Eb F  G  A  Bb (also A#)
Eb F  G  Ab Bb C  D  Eb (also D#)
B  C# D# E  F# G# A# B
Ab Bb C  Db Eb F  G  Ab (also G#)
Gb Ab Bb Cb Db Eb F  Gb (also F#)
Db Eb F  Gb Ab Bb C  Db (also C#)
STOP READING HERE if you want to try to discover the key of “Puʻuanahulu” (the video above) yourself.

I’m going to walk through my process of figuring out this song’s key by ear as I’m writing this. All on the A-string.

While listening to the song, first I play a C# note on my ukulele. This sounds sour so I repeat it a couple times to be sure I’m not just over a weird chord change. Nope. It’s gross.

I slide up one fret to D and immediately it fits better. Bingo card:

D

Next note I try is F. This sounds nice. Bingo card:

D F

Now I drop down to Bb on the 1st fret. It sounds kinda bad even if I stay there for a few seconds so I scoot up to a B note. That’s better, but I think it’s a more dissonant part of the key so I also try going down from Bb to the open A-string. With that contrast (and movement), I think both A and B work. Bingo card:

A B D F

I know from experience that this combination of notes will get me an answer if we refer to the key chart above. You can work through comparing the notes in any way that makes sense to you. In this case, I’ll just go in the order we found the right notes.

Here are the keys that fit an A note:

C  D  E  F  G  A  B  C
F  G  A  Bb C  D  E  F
G  A  B  C  D  E  F# G
A  B  C# D  E  F# G# A
D  E  F# G  A  B  C# D
E  F# G# A  B  C# D# E
Bb C  D  Eb F  G  A  Bb

Here are the keys that have A and B:

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

Not much improvement, but we got rid of the remaining “flat” keys.

Here are the keys that have A, B, and D notes:

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

Finally, we can eliminate all but one key by applying the remaining note, F:

C  D  E  F  G  A  B  C

So now I know that this recording of “Puʻuanahulu” is in the key of C.

Getting Faster & Improving

The more songs you sit and work out in this way, the faster you will get. Eventually you’ll start to subconsciously target the note that will eliminate the most possible keys in one go.

To demonstrate this, I’m going to pick a song I don’t remember ever trying to play before:

Just listening to the guitar opening I can hear that it’s probably in a “guitar key” that sits well on the open strings of a guitar. Guitar keys are E, A, D, G, C.

I’m going to guess D just from the sound of the chord. So I can play a D note to confirm or deny my hunch.

I’ve played enough guitar to have a vague idea what the main open chords sound like. You can probably recognize similar patterns when you hear an ukulele strummed.

It’s a D. I can hear that the D note is the most consonant note possible against the harmony. It’s the one that every chord change pushes back to. Therefore, I know that the key is D.

Let’s try another one.

Sounds like another guitar key. I have to guess C or G from the chord voicings the guitar is playing.

I’ll try C. Ok, it sounds nice and it’s part of the key, but I can hear that it’s not the root note. Which means, depending on how confident I am that G is the next best option I could just try playing a G note and see if it sounds like the root.

However, while I played my C note, the chords changed to the IV chord. The C wasn’t the root of the key, but it WAS the root of the IV chord.

This means the IV chord is C major. And I know that C is the IV in the key of G. So I didn’t even need to play another note.

This may sound like magic, but it’s really just practice. I don’t have perfect pitch, but I’ve developed my sense of relative pitch – something anyone can do.

To prove it, I’m going to choose a weird song that’s less guitar strumming and more technical jazz.

I really have nothing to go on here so it’s luck of the draw. I can hear that it’s a song that probably borrows some harmony from outside the key so it’s going to be even easier to be thrown off.

The intro doesn’t have a lot of harmonic content so I’m just going to listen until the groove and guitar melody comes in.

Focusing your listening on part of the song that is more harmonically obvious is a good trick. Better than guessing the key during a drum solo.

I start with G#. Doesn’t sound like it fits. Sliding up to A or down to G confirms this because both of those notes sound good. Bingo card:

G A

This could be a rather lot of keys:

C  D  E  F  G  A  B  C
F  G  A  Bb C  D  E  F
G  A  B  C  D  E  F# G
D  E  F# G  A  B  C# D
Bb C  D  Eb F  G  A  Bb (also A#)

In writing this, the song went into another part that could very well be a different key so I’m going to rewind back to the guitar melody. In genres where a key change is likely or the next part sounds a little “off,” just stick with the main theme for consistency as you work.

From the G I can hear that the next note down (the melody suggests this) is only a half-step away to F#. I play F# and I’m right! Bingo card:

F# G A

Which leaves us with:

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

At this point I’m jamming. There’s only one note different: C and C#. So almost anything I play is going to work fine.

Or I could just rip the band aid off and see if it’s the key of G or D I’m playing in.

You should ask yourself what you’re trying to accomplish by figuring out the key. If you’re just trying to jam along with solos and fills, a lot of the time you can groove your way to the key.

Don’t stop and figure out what’s going on if you can play something that sounds good with what you’ve already discovered.

I try C. Doesn’t super fit, but it’s not bad because in a funky song like this, the key could be D, but also borrow a C, which is a common blues note.

C# on the other hand has a workable edge to it that makes me think this song is not quite a straight major key. (There are other “modes” based on the key that move the tonality around.)

I don’t super care because I have enough information to make educated guesses about the chords. Figuring these out will tell me the rest of what I need to know. …Or perhaps I will just have to play the rest by ear.

By farting around with some of the common chords in the keys of D and G: D, G, C, A, Em, Bm, etc, I discover that there’s a lot of A major harmony, but that the “home” chord seems to be an Em.

This suggests that the “key” is actually E dorian mode. It’s basically the key of D, but your root is the Em.

While modes might seem like something you need to understand, I would encourage you to pass on them for now. You can make a lot more progress by figuring out the keys of more straightforward songs. There’s nothing wrong with abandoning tunes that seem strange or don’t make sense.

Checklist

That’s basically the process. I can’t emphasize enough that this process is something you will improve at and adapt for the way your mind works.

It will be hard at first. But the more you do it, the easier it will get. The only way to improve is practice.

Here’s a review of the steps you can take to figure out the key of a song by ear. This is not just an ukulele thing too. These directions are pretty much the same for any instrument you might play.

  • Listen
  • Do you have any indicators that point in a certain direction? The sound of a chord? A hunch?
  • Make an educated – or random – guess to eliminate note possibilities
  • As you pin down right or wrong notes, contrast them to the key options they point to
  • Continue making more and more educated guesses until there is only one viable key signature left

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