Table of Intervals in Music Theory

Easily Identify Perfect, Major and Minor Intervals

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In music theory, an interval is the measure of the distance between two pitches. The smallest interval in Western music is a half step. There are several types of intervals, like perfect and non-perfect. Non-perfect intervals can be either major or minor. 

Perfect Intervals

Perfect intervals have only one basic form. The first (also called prime or unison), fourth, fifth and eighth (or octave) are all perfect intervals.

These intervals are called "perfect" most likely due to the way that these types of intervals sound and that their frequency ratios are simple whole numbers. Perfect intervals sound "perfectly consonant." Which means, when played together, there is a sweet tone to the interval. It sounds perfect or resolved. Whereas, a dissonant sound feels tense and in need of resolution.

Non-Perfect Intervals

Non-perfect intervals have two basic forms. The second, third, sixth and seventh are non-perfect intervals; it can either be a major or minor interval.

Major intervals are from the major scale. Minor intervals are exactly a half-step lower than major intervals.

Table of Intervals

Here is a handy table that will make it easier for you to determine intervals by counting the distance of one note to another note in half steps. You need to count every line and space starting from the bottom note going to the top note.

Remember to count the bottom note as your first note.

Perfect Intervals
Type of IntervalNumber of Half-steps
Unisonnot applicable
Perfect 4th5
Perfect 5th7
Perfect Octave12
Major Intervals
Type of IntervalNumber of Half-steps
Major 2nd2
Major 3rd4
Major 6th9
Major 7th11
Minor Intervals
Type of IntervalNumber of Half-steps
Minor 2nd1
Minor 3rd3
Minor 6th8
Minor 7th10

Example of Size or Distance of Intervals

To understand the concept of size or distance of an interval, look at the C Major Scale.

  • Prime/First—C to C
  • Second—C to D
  • Third—C to E
  • Fourth—C to F
  • Fifth—C to G
  • Sixth—C to S
  • Seventh—C to B
  • Octave—C to C

Quality of Intervals

Interval qualities can be described as major, minor, harmonic, melodic, perfect, augmented, and diminished. When you lower a perfect interval by a half step it becomes diminished. When you raise it a half step it becomes augmented.

When you lower a major non-perfect interval a half step it becomes a minor interval. When you raise it a half step it becomes augmented. When you lower a minor interval by a half step it becomes diminished. When you raise a minor interval a half step it becomes a major interval.

Inventor of the Interval System

Greek philosopher and mathematician, Pythagoras was interested in understanding the notes and scales used in Greek music. He is generally considered the first person to call the relationship between two notes an interval. 

In particular, he studied the Greek stringed instrument, the lyre. He studied two strings with the same length, tension, and thickness. He noticed that the strings sound the same when you pluck them.

They are in unison. They have the same pitch and sound good (or consonant) when played together.

Then he studied strings that had different lengths. He kept the string tension and thickness the same. Played together, those strings had different pitches and generally sounded bad (or dissonant).

Finally, he noticed that for certain lengths, the two strings may have had different pitches, but now sounded consonant rather than dissonant. Pythagoras was the first person to designate intervals as perfect versus non-perfect.