Understanding Intervals: The Building Blocks of Harmony


Intervals are the fundamental building blocks of music, forming the basis for melodies, harmonies, and chords. Understanding intervals is essential for any musician looking to deepen their knowledge of music theory and improve their playing, composing, and improvisation skills. In this blog post, we’ll explore what intervals are, different types of intervals, how to identify them, and their significance in music.

What are Intervals?

An interval is the distance between two notes, measured in terms of pitch. Intervals are crucial for understanding the relationships between notes and for constructing scales, chords, and melodies. They can be described by their size (number of steps) and quality (type of interval).

Size of Intervals

The size of an interval is determined by counting the number of letter names (or steps) between the two notes, inclusive of both notes. For example, the interval from C to E spans three letter names: C, D, and E.

Quality of Intervals

The quality of an interval describes the specific sound of the interval and includes terms such as major, minor, perfect, diminished, and augmented.

Types of Intervals

Intervals can be classified into several types based on their size and quality.

Perfect Intervals

Perfect intervals are called “perfect” because they are neither major nor minor and have a consonant, stable sound. They include:

  1. Perfect Unison (P1): The same note played twice (e.g., C to C).
  2. Perfect Fourth (P4): Four steps between notes (e.g., C to F).
  3. Perfect Fifth (P5): Five steps between notes (e.g., C to G).
  4. Perfect Octave (P8): Eight steps between notes (e.g., C to C in the next octave).

Major and Minor Intervals

Major and minor intervals have a more variable quality and can sound either happy or sad:

  1. Major Second (M2): Two steps between notes (e.g., C to D).
  2. Major Third (M3): Three steps between notes (e.g., C to E).
  3. Major Sixth (M6): Six steps between notes (e.g., C to A).
  4. Major Seventh (M7): Seven steps between notes (e.g., C to B).

Minor intervals are one half step smaller than their major counterparts:

  1. Minor Second (m2): One half step between notes (e.g., C to Db).
  2. Minor Third (m3): Three half steps between notes (e.g., C to Eb).
  3. Minor Sixth (m6): Eight half steps between notes (e.g., C to Ab).
  4. Minor Seventh (m7): Ten half steps between notes (e.g., C to Bb).

Augmented and Diminished Intervals

Augmented and diminished intervals are alterations of perfect and major/minor intervals:

  1. Augmented Interval: One half step larger than a perfect or major interval (e.g., C to G# is an augmented fifth).
  2. Diminished Interval: One half step smaller than a perfect or minor interval (e.g., C to Gb is a diminished fifth).

Identifying Intervals

Counting Steps

To identify an interval, count the number of steps (letter names) between the two notes, inclusive of both notes. For example, to find the interval from C to E:

  1. Count the steps: C (1), D (2), E (3).
  2. The interval is a third.

Determining Quality

To determine the quality, consider the number of half steps between the notes:

  1. Major Intervals: Count the half steps between the notes and compare to the major scale.
    • Major Second: 2 half steps
    • Major Third: 4 half steps
    • Major Sixth: 9 half steps
    • Major Seventh: 11 half steps
  2. Minor Intervals: One half step smaller than major intervals.
    • Minor Second: 1 half step
    • Minor Third: 3 half steps
    • Minor Sixth: 8 half steps
    • Minor Seventh: 10 half steps
  3. Perfect Intervals: Count the half steps and compare to the perfect interval.
    • Perfect Unison: 0 half steps
    • Perfect Fourth: 5 half steps
    • Perfect Fifth: 7 half steps
    • Perfect Octave: 12 half steps
  4. Augmented and Diminished Intervals: Adjust perfect and major/minor intervals by a half step.
    • Augmented Fourth: 6 half steps
    • Diminished Fifth: 6 half steps

The Role of Intervals in Music


Intervals form the basis of melodies, determining the pitch relationships between successive notes. Melodic intervals can be stepwise (small intervals) or leaping (larger intervals), creating different melodic contours and expressions.


Chords are built from stacking intervals. For example, a major triad consists of a root note, a major third, and a perfect fifth. Understanding intervals is crucial for constructing and analyzing chords.


Harmony involves the simultaneous sounding of intervals, creating a rich and complex texture. Harmonic intervals can be consonant (stable and pleasing) or dissonant (unstable and tense), contributing to the overall emotional effect of the music.

Ear Training

Training your ear to recognize intervals is essential for musicianship. It improves your ability to identify pitches, transcribe music, and play by ear. Practice singing and identifying intervals to develop your ear.

Practice Tips

  1. Use a Piano or Keyboard: Visualize intervals on a piano keyboard to understand the distance between notes.
  2. Sing Intervals: Practice singing intervals to internalize their sound and improve your ear.
  3. Interval Recognition Exercises: Use apps and online resources to practice identifying intervals by ear.
  4. Apply to Your Instrument: Play intervals on your instrument to reinforce your understanding and develop muscle memory.
  5. Analyze Music: Look at sheet music and identify the intervals used in melodies and harmonies.


Intervals are the building blocks of music, forming the foundation for melodies, harmonies, and chords. By understanding and practicing intervals, musicians can deepen their theoretical knowledge, improve their playing and composing skills, and enhance their overall musicianship. Embrace the study of intervals and unlock new levels of musical understanding and creativity.