Review: Intervals

An interval is the distance between two pitches. Intervals may be melodic or harmonic, thus serving as the basic building blocks of music.

When two pitches occur in succession, the interval is melodic. If the two pitches sound simultaneously, the interval is harmonic.

To determine the size of an interval, count the letter names between the two notes.

An interval larger than an octave can be considered to be a compound interval. For example, a 9th is a compound 2nd (an octave plus a 2nd), a 10th is a compound 3rd (an octave plus a 3rd), and an 11th is a compound 4th (an octave plus a 4th).  Compound intervals function the same as their simple interval versions.

methods to identify intervals above and below a note

A. Count the steps. Smaller intervals can be identified by the number of whole and half steps between the two notes. Larger intervals can be compared to known perfect intervals. For example, the quality of sevenths can be determined by comparing them to the P8, and sixths by comparing them to the P5:

Perfect

 Perfect prime unison P1 Perfect fourth 2 ½ steps P4 Perfect fifth 3 ½ steps P5 Perfect octave P8

Major

 Major second 1 whole step M2 Major third 2 whole steps M3 Major sixth P5 + 1 whole step M6 Major seventh P8 – ½ step M7

Minor

 Minor second ½ step m2 Minor third 1½ steps m3 Minor sixth P5 + ½ step m6 Minor seventh P8 – 1 whole step m7

B. Consider the intervals over the tonic. When identifying an interval, consider the lower note to be the “tonic” in either a major or natural minor key. Reinforce this method by memorizing all major and minor scales and being able to play them at the keyboard.

Intervals Over the Tonic in the Natural Minor Scale

C. Augmented and diminished intervals. Perfect and major intervals can be augmented by raising the top note or lowering the bottom note by a half step. Perfect and minor intervals can be diminished by lowering the top note or raising the bottom note by a half step.

D. Invert large intervals to smaller intervals. When inverting intervals, perfect remain perfect, major become minor, minor become major, diminished become augmented, and augmented become diminished. Note that the interval and its inversion will always add up to 9.

Diminished and Augmented

P1  ⇔ P8 M2 ⇔ m7 m2 ⇔ M7 A4 ⇔ d5 (tritone)
P4 ⇔ P5 M3 ⇔ m6 m3 ⇔ M6 A2 ⇔ d7
M6 ⇔ m3 m6 ⇔ M3 A5 ⇔ d4
M7 ⇔ m2 m7 ⇔ M2 A6 ⇔ d3

Example:

Examples of inverting large intervals to smaller intervals:

Bring the upper note down an octave, identify the interval, and then invert to determine the original interval.

E. Remove accidentals. When identifying intervals with sharps and/or flats, drop the accidentals, use one of the methods described above to identify the interval, then replace the accidentals one by one and note their effect on the interval. Example:

F. Use solfège as a guide. Practice the major interval drills and the minor interval drills in the Diatonic Musicianship section to become familiar with the sound of all the intervals.

Practice