What is an interval?
An interval is the distance between two notes.
|An improper method of measuring intervals on the piano. (There is no "inches to semitones" conversion.)|
The smallest interval (in Western music) is the half step, also called a minor second. As you increase the number of half steps between two notes, the interval gets larger until, eventually, you arrive at an octave (12 half steps apart).
Each interval has its own distinct sound, and this aural aspect of intervals will be the focus of this post.
The following is a list of all the intervals (within the range of one octave; not beyond) and some examples of their corresponding aural identities.
Intervals and Their Aural Identities
- Unison (0 half steps): likely the easiest interval to identify aurally. It's the interval that's created when two people sing the same pitch. It's the interval that piano tuners try to achieve between all three strings of one key.
- Musical example: the first two notes of "America the Beautiful" (Oh beau-)
- Minor 2nd (1 half step): a small, very dissonant interval. In solfeggio, it's the distance from ti to do.
- Musical example: the ominous bass tones from the "Jaws" theme song
- Major 2nd (2 half steps): appears in the first two notes of a major scale.
- Musical example: in the first line of "Happy Birthday," the interval from "-py" to "birth-" (and back down to "-day")
- Minor 3rd (3 half steps): often used to establish a minor tonality and express sadness or grief. In a minor scale, it appears in the leap from the first note to the third note.
- Musical example: the first two notes of the guitar riff from Deep Purple's "Smoke on the Water"
- Major 3rd (4 half steps): often used to establish a major tonality and express happiness or joviality. In a major scale, it appears in the leap from the first note to the third note.
- Musical example: the first interval of "When the Saints Go Marching In"
- Perfect 4th (5 half steps): a rather stable, consonant interval.
- Musical example: the first intervallic leap of "Here Comes the Bride"
- Tritone (6 half steps): this interval presents itself either as an augmented 4th or as a diminished 5th. It it is so dissonant that, dating back to Medieval times, it has been dubbed "diabolus in musica" (the Devil in music). Since the interval has historically served as a symbol of evil, people often associate its sound with danger and the unknown.
- Musical example: the first two notes sung by the choir in "The Simpsons" theme song (The Simp-)
- Perfect 5th (7 half steps): a very stable interval.
- Musical example: the "Winkie Chant" from "The Wizard of Oz"
- Minor 6th (8 half steps): in a second inversion minor triad, the distance from 5 up to 3 (solfeggio: mi up to do).
- Musical example: the first interval in "Black Orpheus"
- Major 6th (9 half steps): in a second inversion major triad, the distance from 5 up to 3 (solfeggio: sol up to mi).
- Musical example: the first two notes of NBC's three-note jingle
- Minor 7th (10 half steps): the inversion of a major second. In a dominant (major-minor) seventh chord, it appears in the leap from the root to the seventh. In this context, the minor 7th has a strong pull toward resolution (as in the following musical example).
- Musical example: from "Somewhere" (Leonard Bernstein's "West Side Story"), the first two notes (There's... a...)
- Major 7th (11 half steps): the inversion of a minor second. In a major seventh chord, it appears in the leap from the root to the seventh. In this context, the major 7th wants to resolve up to the consonant octave.
- Musical example: Norah Jones' "Don't Know Why"
- 8th/Octave (12 half steps): the leap from a note up or down to the next occurrence of the same note name. The frequencies of two notes an octave apart have a ratio of 2:1.
- Musical example: the first big leap in "Somewhere Over the Rainbow"
Symphony of Intervals
I'll leave you with this video (audio only) of a symphony's pre-concert tuning and warm-up. Intervallically speaking, listen for the unisons created immediately after the tuning note is sounded, then listen for all other intervals as each musician warms up individually and deviates from the initial unison. The swirl of different tones and timbres is rather enchanting.