Interval Trainer

Two Strings. Infinite Patterns.

Intervals are the building blocks of every chord, scale, and melody you've ever played. This tool makes them visible, audible, and impossible to forget.

How the tool works

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Root string → Target string

You pick two strings (or the same string). The tool shows the root on one and the interval note on the other — connected by dashed lines.

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12 intervals available

From m2 (1 semitone) to P8 (octave). Every harmonic distance you'll ever need, selectable in one click.

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Sequential or simultaneous

Hear intervals played one note after another (melodic) or both at once (harmonic). Switch instantly with the playback toggle.

▶

Play all pairs

One button plays every root–interval pair across the neck at your chosen BPM. Great for seeing and hearing the pattern in motion.

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Name or interval label

Switch the fretboard labels between note names (C, F#…) and interval numbers (m3, P5…). Two ways of seeing the same thing.

🖱️

Click = root + interval preview

Clicking any green root dot plays it and immediately hints its paired interval note — so every click is a micro ear-training moment, not just a sound check.

Quick Reference — All 12 Intervals

Label	Name	Semitones	Character	Typical use
m2	Minor 2nd	1	Very tense	Chromatic passing, dissonance
M2	Major 2nd	2	Mild tension	Scale steps, melodic movement
m3	Minor 3rd	3	Warm, dark	Minor chords, blues, sad melodies
M3	Major 3rd	4	Bright, stable	Major chords, happy resolutions
P4	Perfect 4th	5	Open, strong	Power chords, quartal harmony
TT	Tritone	6	Unstable, dramatic	Dominant 7th chords, tension
P5	Perfect 5th	7	Hollow, powerful	Power chords, arpeggios, 5ths
m6	Minor 6th	8	Bittersweet	Minor 6th chords, inversions
M6	Major 6th	9	Sweet, open	Major 6th chords, country licks
m7	Minor 7th	10	Bluesy, unresolved	Dominant 7, blues, jazz voicings
M7	Major 7th	11	Dreamy, tense	Maj7 chords, jazz harmony
P8	Octave	12	Pure, doubling	Octave licks, register shifts

Foundation

First Contact — Learn the Three Foundational Intervals Beginner

Before worrying about all 12 intervals, get three into your ears and fingers: the m3 minor third, the P5 perfect fifth, and the P8 octave. These are the skeleton of nearly every chord shape you know. Once they sound familiar — not just look familiar — everything else starts to fall into place.

Setup — work through each

Root stringE (low)

Target stringA

Interval — round 1m3

Interval — round 2P5

Interval — round 3P8

PlaybackSequential

What to do

Select E as root, A as target, m3 as interval. Hit "Play all" and just listen — don't look at fret numbers. Hear the minor third sound.
Click any green dot individually. Immediately click its paired blue dot. Hear the pair, say the interval name aloud: "minor third."
Switch to Simultaneous. Same dots — but now both notes ring together. Notice how the harmonic sound differs from the melodic one.
Repeat the full cycle for P5 and P8. By the end you should hear something different in each — power, warmth, or a hollow ring.

Switch on Interval num mode before playing. Now the blue dots show m3, P5, or P8 instead of note names. This disconnects the sound from a specific pitch and trains you to hear the relationship, not the note.

Challenge: After listening to all three intervals, close your eyes and ask someone to click Play all on one of them. Can you identify which interval you're hearing before opening your eyes? This is basic interval ear training — and it gets fast with repetition.

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Shape Hunting — The Same Interval on Every String Pair Geometry

On a guitar, every interval has a characteristic shape that stays roughly consistent across string pairs — with one important exception between the G and B strings, where standard tuning breaks the pattern. This exercise makes that geometry visible. Once you see that a P5 always looks like "same fret + 2 strings up," you stop counting semitones and start recognising shapes.

Setup — rotate through all string pairs

IntervalP5

Pair 1E → A

Pair 2A → D

Pair 3D → G

Pair 4G → B ⚠️

Pair 5B → e

What to observe

For pairs 1–3 and pair 5: notice the fret offset between each green dot and its blue partner. It's the same number — the shape is consistent.
On pair 4 (G → B): the offset is different by one fret. This is the famous tuning exception — the B string is tuned a semitone lower than the pattern would predict. Every guitarist must memorise this shift.
Repeat for m3 and M3. See how the offset changes with each interval — smaller intervals = smaller fret gap.
Try the same-string setup: set Root = Target (same string). See how the interval becomes a pure fret distance on one string instead of a two-string shape.

P5 shape across string pairs (standard tuning)

→ offset: +2 frets up on A string

⚠️ G → B exception: the P5 target shifts one fret higher compared to all other string pairs. This affects every interval crossing that string boundary.

Challenge: Set P4 (perfect fourth) and work through all string pairs. A P4 is the inverse of P5 — together they add up to an octave. Can you spot the consistent shape? Now you understand why power chords look identical on every string group except G–B.

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Ear Training

Tension Game — Hear Stable vs. Unstable Intervals Ear Training

Not all intervals feel equal. Some sound settled and complete — the ear wants to stay there. Others feel like they're pulling somewhere, like a stretched rubber band waiting to release. Learning to feel this tension is more useful than memorising interval names, because it lets you predict how a phrase will sound before you play it.

Tension spectrum — try in this order

P8 P5Stable

M3 m3 M6Consonant

P4Neutral

m7 M2 m6Mild tension

M7 m2Sharp tension

TTMaximum tension

The listening exercise

Set playback to Simultaneous and BPM to any value (you'll use Play all). Listen to each interval as a harmonic sound, not as two separate notes.
After each interval plays, rate it on a 1–5 tension scale in your head. Don't look at the table above — form your own impression first.
Play P5 → TT → P5 alternately a few times. This contrast is the sharpest possible: maximum stability vs. maximum tension. Your ear will calibrate quickly.
Now play m3 → M3 → m3 alternately. Same root, one semitone difference. Hear the major/minor emotional shift — this is the sound of sadness vs. brightness.

The TT tritone was historically called diabolus in musica — the devil in music — because of how unsettled it sounds. Play it once, then immediately play a P5. That movement (TT resolving to P5) is the harmonic engine of every dominant chord in Western music.

Challenge: Set E as root, A as target, then use Play all at 60 BPM on Simultaneous mode. Go through every interval from m2 to P8 in order. By the end you'll have heard the entire tension arc from maximum dissonance through neutral to the brightness of M7.

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Technique

Double Stops — Play Every Interval Pair as a Riff Technique

A double stop is two notes played simultaneously on adjacent strings — one of the most expressive sounds in blues, country, and rock. The Interval Trainer shows you exactly where every double stop lives. Instead of memorising lick shapes, you'll understand why a double stop sounds the way it does — because you can see and hear the interval before you play it.

Classic double stop intervals

Root stringsD + G (adjacent)

Blues double stopm3 or M3

Country soundM6

Rock power feelP5

PlaybackSimultaneous

BPM60–80

Practice method

Set D as root, G as target, select m3. Hit Play all — each pair is a double stop position. Listen to the bluesy sound.
Click each green dot manually (not Play all). Immediately pick that pair on your guitar — two strings, same position. Match what you hear in the tool.
Move up the neck pair by pair. You're playing a double stop run — a classic blues move, now fully visualised.
Switch to M6 and repeat. Hear how the country/southern rock sound appears. Same technique, completely different flavour.

Try setting Label mode: Interval num. Now every blue dot shows "m3" or "M6" instead of a note name. When you play a double stop on your guitar, you'll associate the sound with the interval name directly — not with the fret position. That's the mental shift that makes you a faster improviser.

Challenge: Set G as root, B as target (crossing the tuning break), select M3. Notice that the fret positions look different from the D→G pair with the same interval. This is the G→B exception in action. Play both string pairs at the same fret — they sound different. The tool shows you exactly where the adjustment happens.

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Chord Decoder — Reverse-Engineer Any Two-Note Voicing Theory

When you play a barre chord, you're stacking intervals on top of a root. This exercise reverses the usual direction: instead of building up from theory, you take any two-string shape you already play and find out which interval it is. The result is that familiar chord shapes gain a theoretical explanation — and you discover that many "different" shapes are actually the same interval in a different position.

Example — open E chord dissected

E (open) → A (fret 2)P5

A (fret 2) → D (fret 2)P4

D (fret 2) → G (fret 1)M3

G (fret 1) → B (open)m3

B (open) → e (open)P4

How to use the tool for this

Pick any two adjacent strings of a chord you know. Set them as Root and Target in the tool.
Try each interval until the green dot at your fret position has a blue partner at the correct fret. That's your interval.
Switch to Interval num label mode — the blue dot now names the interval directly. Check it matches your search.
Do this for every adjacent string pair of the same chord. You've just mapped the entire chord as a stack of intervals.

Once you've mapped a chord's intervals, try substituting one: if a string pair is M3, what happens if you shift it to m3? You're now modifying a chord by interval — thinking like an arranger, not just a player. The tool makes the result immediately visible and audible before you pick up the guitar.

Challenge: Map the Am chord the same way you mapped E major above. Compare the two chord maps side by side. You'll find that Am and E major share several identical interval pairs — which is why they share so many voicing shapes on the neck. This is the root of relative key theory, seen from the bottom up.

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Creative

Speed Drill — BPM Interval Runs as a Warm-Up Game Speed

Knowing where intervals live is one thing. Being able to play them cleanly at tempo is another. This session turns the tool's Play all feature into a metronome-driven warm-up game: the screen shows you where each note lands, and your job is to be ahead of the tool — clicking (or playing on guitar) before the animated dot lights up. It trains both speed and spatial anticipation at the same time.

Warm-up ladder

Start BPM50

Target BPM120

Step up+10 BPM

PlaybackSequential

IntervalP5 (start)

String pairE → A

The drill

Set BPM to 50, select P5 on E→A, hit Play all. Follow along on your guitar — play each root dot, then its blue partner, in time with the tool.
When you can play the full run cleanly twice in a row, raise BPM by 10. Repeat.
At your max comfortable BPM, switch interval to m3. The shape changes — your hands need to re-adjust. That's the useful part.
Rotate string pair: A→D, then D→G. Same BPM, same interval, different geometry. Each crossing is a small new challenge.

Try the drill in Simultaneous mode at a moderate BPM. Now you're strumming double stops in time with a click. This is exactly what a rhythm guitarist does when adding harmonic colour — and it sounds musical almost immediately because the interval relationships are already clean.

Challenge: Set the TT tritone on E→A. Run it at 80 BPM Sequential. The tritone jumps are awkward and uncomfortable — that's the point. Uncomfortable intervals at tempo are the fastest way to build fretboard fluency, because they force your hand to navigate positions it doesn't default to. Once TT feels easy, everything else does too.

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