Intervals: the distance between notes.

1. What is an interval?

An interval is the distance between two notes. C to D is a second. C to E is a third. C to G is a fifth. Intervals can be played one after another or at the same time.

2. Interval numbers

To find the number, count letter names including both notes. C to E is C-D-E, so it is a third. D to A is D-E-F-G-A, so it is a fifth. Accidentals do not change the number; they change the quality.

3. Interval qualities

Intervals have qualities such as major, minor, perfect, augmented, and diminished. Seconds, thirds, sixths, and sevenths are usually major or minor. Unisons, fourths, fifths, and octaves are usually perfect. If an interval is made wider, it can become augmented. If it is made narrower, it can become diminished.

4. Melodic and harmonic intervals

A melodic interval happens when notes are played one after another. A harmonic interval happens when notes sound together. Pianists need both: melodies move by melodic intervals, while chords are made from harmonic intervals.

5. Why intervals matter for ear training

If you can hear intervals, you can learn melodies faster, recognize chord colors, and sight-read more intelligently. Start with seconds, thirds, fourths, fifths, and octaves before trying every possible interval.