♪ Musical Intervals Guide

This guide walks you through ear training for musical intervals: you will understand what an interval is, learn to recognize its sound characteristics, and discover how to get the most out of the exercise.

1. What is a musical interval?

An interval is the sonic distance between two notes. It is the fundamental building block of music: chords, melodies and harmonies are all constructed from intervals.

Distance is measured in semitones — the smallest unit of the Western chromatic scale. On a piano keyboard, one semitone is the distance between any key and the immediately adjacent key (white or black).

📌 Practical example From C to D♭ there is 1 semitone. From C to D there are 2. From C to E there are 4.

Ascending, descending and harmonic intervals

Ascending: the lower note sounds first, then the higher one.
Descending: the higher note sounds first, then the lower one.
Harmonic: both notes sound simultaneously, as in a chord.

The same distance sounds different in each case: training your ear across all three modes is essential for developing a complete musical hearing ability.

2. Interval qualities

Intervals are not just numerical distances: they have a quality that describes their sonic character.

Perfect — stable, open, neutral sound. Examples: 4th, 5th, octave.
Major — bright, open sound. Examples: major 2nd, 3rd, 6th, 7th.
Minor — darker, more melancholic sound. One semitone less than the corresponding major interval.
Tritone (Augmented/Diminished) — the most unstable and tense interval, exactly halfway through the octave. In the Middle Ages it was called diabolus in musica.

3. Interval table

Below are all the intervals in the exercise, from smallest to largest, with the number of semitones, the sonic character, and a famous musical example to help you remember each one.

Interval	Semitones	Character	Famous example
Minor 2nd	1	Maximum tension, dissonant	Jaws — the two notes of the main theme
Major 2nd	2	Natural melodic step	Happy Birthday — the first two notes
Minor 3rd	3	Melancholic, introspective	Smoke on the Water (Deep Purple) — opening riff
Major 3rd	4	Bright, joyful	When the Saints Go Marching In — opening
Perfect 4th	5	Solemn, stable	Here Comes the Bride — the first two notes
Tritone	6	Unstable, unsettling, tense	The Simpsons theme opening; Black Sabbath
Perfect 5th	7	Powerful, hollow, heroic	Star Wars main theme; Twinkle Twinkle
Minor 6th	8	Expressive, bittersweet	The Entertainer (Scott Joplin) — opening
Major 6th	9	Warm, open, nostalgic	My Way (Frank Sinatra) — «And now…»
Minor 7th	10	Bluesy, suspended	Somewhere (West Side Story) — «There's a place»
Major 7th	11	Tense, brilliant, almost dissonant	Take On Me (A-ha) — opening keyboard riff
Octave	12	Full, conclusive, resolved	Somewhere Over the Rainbow — the first two notes

Extended intervals (level 5)

Extended intervals are compound intervals: they exceed the octave and correspond to the basic intervals transposed one octave higher.

Interval	Semitones	Compound equivalent
Minor 9th	13	Octave + Minor 2nd
Major 9th	14	Octave + Major 2nd
Minor 10th	15	Octave + Minor 3rd
Major 10th	16	Octave + Major 3rd
Perfect 11th	17	Octave + Perfect 4th

4. How the exercise works

The concept is simple: the program randomly picks an interval, plays it, and you must identify it by clicking the corresponding button in the grid.

Interface walkthrough

▶ Play button

Press to hear the current interval. Once you have answered, press again to move to the next interval.

♪ Staff

Shows the root note (in yellow) before you answer. After a correct answer, the second note also appears (in green), so you can read the interval on the staff.

🎹 Piano keyboard

The root note is highlighted in yellow. You can click the keys to hear individual notes while searching for the interval. You can also answer directly by clicking the key you think is the upper note: if correct it turns green, otherwise red.

■ Interval grid

Buttons available for the current level are lit up; those not included in the level appear dark. Click the one you think matches the interval you heard. If wrong, the button turns red — click it again to hear that interval and compare it with the correct one.

🏆 Score

The score in the top right shows correct first-attempt answers / total questions. If you answer correctly on the first try you get the point; if you miss even once, the question counts as wrong even if you eventually find the right answer.

5. MIDI Input (Physical Keyboard)

You can connect a real USB MIDI keyboard to your computer to perform the exercises naturally.

The MIDI input is always active (no configuration needed). It supports hot-plugging: you can plug in the USB cable before or after opening the browser.
Exact octave matching: you must play the second note of the interval in the exact octave shown on the screen (calculated from the root note displayed in yellow). Notes played in different octaves will be ignored.
All notes pressed on the physical keyboard are immediately reflected on the virtual keyboard on screen, turning green (if correct) or red (if wrong) and submitting the corresponding answer.

6. Mode selector

You can choose how to hear the intervals:

↑ Ascending — the lower note sounds first, then the higher one. The most common form and the ideal starting point.
↓ Descending — the higher note sounds first, then the lower one. The same interval sounds very different in descending form!
⇅ Harmonic — both notes sound together. The hardest mode because you have no melodic contour as a reference.

💡 Tip Always start in Ascending mode. Once you know the intervals well, switch to Descending then Harmonic — you'll find they are three distinct training challenges even for the same intervals.

7. Difficulty levels

The exercise has 5 levels that progressively add more intervals to the grid:

1 — Basic Only Perfect 4th, Perfect 5th and Octave — the three most recognisable intervals. Perfect for beginners.
2 — Easy Minor 3rd and Major 3rd are added — the intervals of triads.
3 — Medium Major 2nd, Minor 6th and Major 6th also join.
4 — Expert All 12 chromatic intervals, including the hardest ones such as Minor 2nd, Tritone and Major 7th.
5 — Extended Five compound intervals beyond the octave are added (Minor 9th through Perfect 11th).

⚠️ Don't rush to the next level It is better to reach a good score at the current level (at least 80% first-attempt) before increasing the difficulty.

8. Root note selector

You can choose which note to use as the starting point for intervals:

⟳ Random — the root note changes with every question, from C3 to C5. The most realistic and complete mode.
Fixed note — click one of the ◀ ▶ arrows or the note itself to lock a specific note. Useful in the early learning stages to eliminate one variable and focus purely on the distance.

💡 Learning strategy Start with root fixed on C4 (middle C). Once you can recognise intervals from C reliably, switch to Random mode to generalise the skill to any key.

9. Recognition strategies

The most effective method for learning to recognise intervals is to associate each one with a reference melody you know well. When you hear an interval, the melody "fires" automatically in memory.

Building your interval vocabulary

Listen to the interval in the exercise.
Mentally sing the reference melody that begins with that interval.
Compare the feeling with the melodies of the other intervals.
Repeat until the association becomes immediate.

Recognition by contrast

Another very effective method is learning to distinguish intervals in pairs:

Minor 2nd vs Major 2nd — both are "steps", but the minor is harsher and closer, the major is natural and melodic.
Minor 3rd vs Major 3rd — the minor has a dark/sad colour, the major is open/bright.
Perfect 4th vs Tritone — the 4th is stable, the tritone is unstable and "wants" to resolve.
Perfect 5th vs Minor 6th — the 5th is powerful and hollow, the 6th is more "singable" and expressive.
Minor 7th vs Major 7th — the minor is "bluesy", the major is tense and almost dissonant.

Direction matters

An ascending interval and the same interval descending evoke different emotional responses. The ascending 5th (C→G) sounds heroic; the descending 5th (G→C) sounds conclusive. Train both directions separately.

💡 Short, frequent sessions Ear training works best with 10–15 minutes a day rather than occasional long sessions. Regularity is the key to consolidating the neural connections that enable automatic recognition.