An interval is the distance between two pitches. Intervals are the building blocks of scales, chords and melodies, and each size has a recognisable sound and a specific number of semitones.
Learning intervals is more useful than memorising isolated note lists because the same relationships move to every key.
Semitone and whole tone
One fret is a semitone. Two frets are a whole tone.
Number and quality describe the interval
The number counts letter names, while the quality specifies the exact size. C to E is a major third; C to E-flat is a minor third. Both are thirds because C-D-E spans three letter names.
Quality
Words such as major, minor, perfect, augmented and diminished specify the exact size.
Harmonic and melodic
Two notes played together form a harmonic interval; played one after another they form a melodic interval.
The same interval appears in many shapes
A perfect fifth can be played on adjacent strings as a power chord or across other string combinations. The fretboard shape changes around the B string, but the pitch distance remains seven semitones.
Intervals can be melodic or harmonic
A melodic interval is heard as two notes in sequence; a harmonic interval is heard simultaneously. The pitch distance is the same, but the ear may recognise it differently in a melody and inside a chord.
Put the idea on the fretboard
- Play a root followed by a major third, minor third, perfect fourth and perfect fifth.
- Play each from several roots.
- Sing the second note before playing it to connect the fretboard distance with the sound.
- Connect interval shapes to familiar chords.
When the idea still feels confusing
You count frets but ignore note letters
Fret distance gives size, but interval naming also uses letter count.
You memorise shapes without sound
Play and sing intervals so the ear learns the relationship.
You memorize names but cannot recognise them
Use short reference melodies and repeated ear tests. Interval knowledge becomes practical when the sound, semitone distance and fretboard shape are linked.