Reading Music · Chapter 10 of 12

Intervals and Chords

An interval is the distance between two notes. Stack two of the right intervals and you have a chord.

To name an interval, count the letter names from the lower note to the higher one, counting both notes. C up to E is C, D, E: three letters, so it’s a third. C up to G is C D E F G: a fifth.

From C up: a 2nd, 3rd, 4th, 5th, 6th, 7th and an octave. Two notes played together like this are a harmonic interval; one after the other, a melodic interval.

Seeing intervals on the staff

2nd

Line to the next space, or space to the next line: a step. Together, the two notes sit side by side.

3rd

Line to the next line, or space to the next space: a skip.

5th

Line to line with one line between, or space to space with one space between.

Odd numbers (3rd, 5th, 7th) go line to line or space to space. Even numbers (2nd, 4th, 6th, octave) go from a line to a space, or a space to a line.

Major, minor and perfect

Two intervals can have the same number but a different size. C to E and D to F are both thirds, but C to E spans 4 half steps and D to F only 3. The bigger one is a major third, the smaller a minor third. Seconds, thirds, sixths and sevenths come in major and minor. Unisons, fourths, fifths and octaves are called perfect.

IntervalHalf stepsFrom C
minor 2nd1C–D♭
major 2nd2C–D
minor 3rd3C–E♭
major 3rd4C–E
perfect 4th5C–F
augmented 4th or diminished 5th6C–F♯ or C–G♭
perfect 5th7C–G
minor 6th8C–A♭
major 6th9C–A
minor 7th10C–B♭
major 7th11C–B
perfect octave12C–C

Starting on C, every interval up to a white key is major or perfect. On other notes, some come out minor: E up to G is a minor third (3 half steps), and F up to B is an augmented fourth (6).

Chords and triads

A chord is three or more notes played together. The most common is the triad: three notes stacked in thirds. The bottom note is the root, which names the chord; then come the third and the fifth. On the staff, a triad in this position looks like a little snowman: three lines in a row, or three spaces in a row.

Major triad

Root, a major third up (4 half steps), then a minor third more. Bright and settled. C major: C E G.

Minor triad

Root, a minor third up (3 half steps), then a major third more. Darker. A minor: A C E.

The major chords C, F and G, then the minor chords A minor, D minor and E minor. All white keys, all built in thirds. Press Hear it to compare the bright major chords with the darker minor ones.

In C major, the chords built on the 1st, 4th and 5th notes of the scale (C, F and G) are the ones you’ll meet most. Many simple songs use only these three; the left hand of Jingle Bells on this site plays their roots.

Remember

  • Count letter names, both ends included: C to E is a 3rd.
  • Same number, different size: major, minor or perfect, counted in half steps.
  • A triad is root, third and fifth, stacked in thirds. Major: 4 + 3 half steps. Minor: 3 + 4.

Songs that use this

@teddyrookbook GitHub