The Minor Thirteenth: A Comprehensive Guide to This Expressive Interval

What Is a Minor Thirteenth?

A minor thirteenth is a compound interval that spans 20 semitones (or 10 whole steps) above the root note. It is the combination of an octave plus a minor sixth. In terms of scale degrees, it is the 13th note of the minor scale built on the root. For example, in the key of C, the minor thirteenth would be C to Ab (C-D-E-F-G-A-Bb-C-D-E-F-G-Ab).

Historical Context and Musical Significance

The minor thirteenth gained prominence in the late 19th and early 20th centuries as composers began exploring more complex harmonies. It became particularly important in jazz, where extended chords are commonplace. The tension and color provided by the minor thirteenth make it a favorite for creating rich, sophisticated harmonies.

Technical Construction

The minor thirteenth can be constructed using the following formula:

• Root
• Minor third (3 semitones)
• Perfect fifth (7 semitones)
• Minor seventh (10 semitones)
• Minor ninth (13 semitones)
• Perfect eleventh (17 semitones)
• Minor thirteenth (20 semitones)

Practical Applications

The minor thirteenth is often used in jazz and contemporary music to add color and tension to chords. It is commonly found in minor key progressions and can be used to create a sense of melancholy or sophistication.

Examples in Different Genres

Jazz: In jazz, the minor thirteenth is often used in minor seventh chords (e.g., Cm13). A typical voicing on piano might be C-Eb-G-Bb-D-F-Ab.

Classical: Composers like Debussy and Ravel used the minor thirteenth to create lush, impressionistic harmonies.

Rock/Pop: While less common, the minor thirteenth can be found in more harmonically sophisticated rock and pop songs, often as part of a borrowed chord.

Progressive Exercises

Here are some exercises to help you master the minor thirteenth:

• Level 1: Play a minor thirteenth interval on your instrument and sing along to internalize the sound.
• Level 2: Practice constructing minor thirteenth chords in different keys.
• Level 3: Incorporate minor thirteenth chords into your improvisations and compositions.

Common Usage in Music

The minor thirteenth is frequently used in the following contexts:

• As part of a minor ii-V-i progression in jazz
• In modal interchange, where a chord from the parallel minor is borrowed
• As a passing chord to add harmonic interest

Ear Training Tips

To recognize a minor thirteenth by ear, listen for its characteristic tension and resolution. It often resolves down to a perfect twelfth or up to a major thirteenth. Practice identifying it in context by listening to jazz standards and classical pieces that feature extended harmonies.