The Comprehensive Interval Guidebook

Your all-in-one guide to musical intervals.

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Welcome to the ultimate guide to musical intervals! Whether you're just starting your musical journey or looking to solidify your understanding, this handbook will cover everything you need to know. Intervals are the fundamental building blocks of both melody and harmony. Mastering them is like learning the grammar of music—it unlocks a deeper level of fluency, comprehension, and creativity.

What is an Interval?

In music, an interval is simply the distance in pitch between two notes. This distance can be described in terms of its size (e.g., a 3rd, a 5th) and its quality (e.g., major, minor, perfect). Understanding these two components is the key to identifying any interval you encounter.

Melodic vs. Harmonic Intervals

It's crucial to distinguish between two ways intervals can appear:

  • Melodic Intervals: The notes are played one after another, in sequence. This is how intervals create melodies. Think of the first two notes of "Twinkle, Twinkle, Little Star"—that's a melodic interval (a perfect 5th).
  • Harmonic Intervals: The notes are played at the same time. This is how intervals create harmony and chords. When you strum a C major chord on a guitar, you're playing several harmonic intervals at once.

While they appear differently, the method for naming them is the same.

Naming Intervals: Size and Quality

Step 1: Determine the Interval Size (The Number)

The size of an interval is its numerical name. To find it, you simply count the lines and spaces on the staff from the lower note to the upper note, including both notes themselves. For example, from C to G, you would count C(1), D(2), E(3), F(4), G(5). Therefore, the interval is a 5th.

Step 2: Determine the Interval Quality (The Description)

The quality describes the precise distance in semitones (half-steps) and gives the interval its unique flavor. The main qualities are Major, Minor, Perfect, Augmented, and Diminished.

The easiest way to determine quality is to think of the major scale of the lower note. If the upper note is in the lower note's major scale, the interval will be either Major or Perfect.

  • Perfect Intervals: Unisons (1sts), 4ths, 5ths, and Octaves (8ths) are called 'Perfect' when the top note is in the bottom note's major scale. They sound very stable and open.
  • Major Intervals: 2nds, 3rds, 6ths, and 7ths are 'Major' when the top note is in the bottom note's major scale. They generally sound bright and happy.
  • Minor Intervals: If you take a Major interval and make it one semitone smaller, it becomes Minor. Minor intervals often sound more subdued, sad, or serious.
  • Augmented Intervals: If you take a Major or Perfect interval and make it one semitone larger, it becomes Augmented. These sound tense and dissonant.
  • Diminished Intervals: If you take a Minor or Perfect interval and make it one semitone smaller, it becomes Diminished. These also sound very tense and unstable.

The Sound of Intervals

Theory is one thing, but music is about sound! The best way to learn intervals is to train your ear to recognize their unique character. Many musicians associate intervals with the opening notes of familiar songs:

  • Minor 2nd: "Jaws" theme
  • Major 2nd: "Happy Birthday" (first two notes)
  • Minor 3rd: "Greensleeves"
  • Major 3rd: "Oh, When the Saints"
  • Perfect 4th: "Here Comes the Bride"
  • Tritone: "The Simpsons" theme
  • Perfect 5th: "Twinkle, Twinkle, Little Star"
  • Minor 6th: "The Entertainer" (3rd and 4th notes)
  • Major 6th: "My Bonnie Lies Over the Ocean"
  • Minor 7th: "Somewhere" (from West Side Story)
  • Major 7th: "Take on Me" (chorus)
  • Octave: "Somewhere Over the Rainbow"

Why Intervals Are the Key to Music

Understanding intervals is the key that unlocks almost all other areas of music theory.

  • Building Chords: Chords are just stacked intervals. A major chord is a major third with a minor third on top. A minor chord is a minor third with a major third on top.
  • Understanding Scales: Scales are simply a sequence of intervals. The major scale formula is a pattern of whole and half steps (which are just major and minor 2nds).
  • Songwriting and Improvisation: Consciously choosing intervals allows you to craft specific emotions and melodic contours in your music.
  • Ear Training: Learning to identify intervals by ear is one of the most powerful skills a musician can possess. It allows you to learn songs faster, improvise with confidence, and understand music on a deeper level.

Conclusion

Intervals are the essential DNA of music. Every melody you've ever hummed and every chord that has ever moved you is built from them. Taking the time to understand, identify, and hear intervals will pay huge dividends in your musical journey, transforming the way you listen, play, and create music.