Here’s my approach to “position playing” on the ukulele, by which I mean the ability to play every note and every chord in a given key while keeping the fretting hand in a fixed location over the fretboard.

Download diagram: Diatonic chord boxes

The approach is based around this moveable major chord shape:

That’s a C-shape major chord. It’s special because it’s a convenient box shape that spans one full octave, so it contains every note in the scale and every chord in the key.

When using this shape to play the I chord (ex. C major, in the key of C), the notes of the major scale are distributed within it like this:

I-chord box

What’s really convenient about this position is that I can make a barre with my index finger and anchor it there. Only my other three fingers need to move most of the time. Without moving my barre finger I can play the entire scale, along with five of the seven diatonic chords.

What are diatonic chords?

“Diatonic chords” are the chords that occur naturally in a key, composed of only the notes found in the key (or scale). Every key has seven “diatonic triad” chords, which are three-note chords made from notes of the scale.

These seven diatonic chords are commonly labeled with roman numerals, I-VII. By convention, uppercase numerals are used for major chords (ex. V) and lowercase are used for minor chords (ex. vi).

Diatonic chords are constructed by “stacking thirds” – stacking up every other note in the scale, starting with the chord’s root note. The I chord is composed of the 1-3-5 notes from the scale, the ii chord is 2-4-6, etc. The interval between the first two chord tones is either a major third or a minor third, which determines whether it’s a major or minor chord.

Here are the diatonic chords in a major key, with the C major key shown for reference.

I ii iii IV V vi vii°
Major minor minor Major Major minor dim
1-3-5 2-4-6 3-5-7 4-6-1 5-7-2 6-1-3 7-2-4
C Dm Em F G Am

Note that the vii is a diminished chord, which is rarely used in this form.

For more information, see this Chord Construction article at

Diatonic chords in the I-box

Here are my preferred shapes for the diatonic chords inside the I-chord box. I’ve included the name of the chord in the key of C, for reference. These shapes can be used in any key, of course.

When I play these chord shapes I tend to keep my barre finger in place all the time, except when playing the iii and V chords (which can be played by temporarily sliding the barre up two frets).

I Maj (C)
ii min (Dm)
iii min (Em)
IV Maj (F)
V Maj (G)
vi min (Am)
V7 (G7)

Technically, the vii chord should be a diminished chord, but I rarely use that so I substitute the dominant V chord (V7) when I practice. The V7 chord has all the same notes as the vii diminished, with an added “5” (which I can just omit if I want to play a true diminished triad).

To explore these and other related chord shapes, try my little web app: Ukulele chord box explorer.

Three positions on the fretboard

There are three major chords in a given key: the I chord, the IV chord, and the V chord. So this chord-box trick can be applied in three different positions on the fretboard.


The scale shapes within these three boxes are very similar, except one note differs by one fret from the I-chord. (Tip: notice that the 2,4,5, and 7 in the I-chord are arranged in a diamond shape. Imagine that diamond shape overlaid on the IV and V chords to see how one note differs.)

When I’m playing one of these major chord shapes, I can tell if it’s the I, IV, or V chord by trying those differing notes to hear which one sounds right.

The IV-chord box

The scale shape in the IV-chord box is the same as the I-chord box with the following exception: the 7 in the IV-chord box would be a sharp 4 (#4) in the I-chord box.

Incidentally, the sound of that #4 is the sound of the Lydian mode; a distinctive, alien sort of sound that is easy to identify. I use this sound to help orient me when I’m not sure which chord box I’m in.

Here are my preferred shapes for the diatonic chords inside the IV-chord box.

I Maj (C)
ii min (Dm)
iii min (Em)
IV Maj (F)
V Maj (G)
vi min (Am)
V7 (G7)

The V-chord box

The scale shape in the V-chord box is the same as the I-chord box with the following exception: the 4 in the V-chord box would be a flat 7 (♭7) in the I-chord box.

The sound of that ♭7 is the sound of a dominant 7 chord (and also the sound of the Mixolydian mode). Only the V chord can be played as a dominant 7 (using only diatonic notes). I use this sound to help orient me when I’m not sure which chord box I’m in.

Note that the V-chord box overlaps about half of the IV-chord box, so several of the diatonic chords are the same in both boxes.

Here are my preferred shapes for the diatonic chords inside the V-chord box.

I Maj (C)
ii min (Dm)
iii min (Em)
IV Maj (F)
V Maj (G)
vi min (Am)
V7 (G7)

A note about minor keys

I use this same approach for position playing in natural minor keys, but out of laziness I orient the numbering around the relative major key. Relative major and minor keys have the exact same chords and scale notes, they’re just numbered differently.

The relative major of a minor key is the note a minor third above the root (i.e. the third scale degree). So the relative major of Am is C, and the relative major of Em is G, etc.

For example, to play in Em I use the chord positions and scale from G major. I think of Em as the vi chord, rather than the i. Then G is the I chord, Am is the ii chord, etc.


Using these positions makes playing feel more effortless because there is less jumping around. The chord changes and scale intervals become muscle memory. It also helps me internalize the relationships between the different chords in the key – it’s clear how similar chords are when I’m only moving one finger to switch between them.


One way I practice these positions is by picking one chord box and playing through the diatonic chords in order: I-ii-iii-IV-V-vi-V7-I. While doing that I focus on the chord number and the scale degree under the root note of the chord.

I also practice them by picking a song and playing the chord changes in all three chord-box positions, focusing on both the names of the chords and their number.

I use this diagram for reference: Diatonic chord boxes.

I also made a small web app for exploring these chord boxes and other common non-diatonic chords within them: Ukulele chord box explorer.

More on the theory

For more information on the theory behind all this, I highly recommend these resources:

Both sites are excellent resources for guitar instruction in general.