Locomotion

Summary

Understanding the Form and Harmony of “Locomotion”

The Structure: AABA Blues Form

“Locomotion” follows an AABA form, where the A section is a classic 12-bar blues progression, and the B section acts as a bridge with chromatic dominant movement.

• A Sections: Each A section is a 12-bar blues, played twice per chorus.
• B Section (Bridge): An 8-bar passage characterized by a descending chromatic dominant line, introducing harmonic tension before resolving back to the blues.

The Blues Foundation in A Sections

The blues sections adhere closely to traditional blues harmony but with subtle variations:

• The head (melody) stays mostly on the tonic chord without moving to the IV chord on the second bar.
• During solos, the IV chord is introduced on the second bar, enriching harmonic variety.
• The 12-bar blues progression features classic tonic (I), subdominant (IV), and dominant (V) functions.

Harmonic Analysis Highlights

• The progression includes common jazz harmonic movements such as ii–V–I sequences.
• Dominant chords on the bridges function as tritone substitutes.
• These substitutions add chromatic color and voice-leading sophistication without departing from the blues feel.
• Sharp 11 alterations appear sporadically but are not heavily emphasized, showing Coltrane’s preference for straightforward dominant sounds over complex tensions in this piece.

Voice Leading and Resolution

• The bridge’s harmonic movement demonstrates smooth voice leading, using descending chromatic lines to resolve dominant chords effectively.
• The interplay of sub V7 chords and secondary dominants creates a rich harmonic palette that supports improvisation.

Melodic Concepts and Motifs in “Locomotion”

The Core Motive

Coltrane’s melody in “Locomotion” is built around a simple motive emphasizing the fifth, flat seventh, and tonic notes, which is transposed and slightly extended throughout the form.

• The motive is repeated and varied during the A sections.
• The bridge section is improvised.

Improvisational Approach

• Coltrane begins solos with triads and tetrads (chord tones), focusing on core harmony.
• He employs chromatic approaches to triads, adding tension and release.
• The solo features augmented triads, backdoor dominant substitutions, and secondary dominants, enriching the harmonic vocabulary.

Chord Scales and Soloing Techniques

Using Mixolydian and Dorian Modes

• Over dominant chords, Coltrane primarily uses the Mixolydian scale, sometimes adding flat 9 and flat 13 tensions for color.
• For minor chords, the Dorian mode is utilized, emphasizing natural 6th and 9th extensions.

Alterations and Substitutions

• Sharp 11 alterations occur but are sparingly used.
• Coltrane frequently plays a dominant chord minor third above the target chord (e.g., C7 over A7), which introduces altered tensions such as sharp 9, flat 9, and flat 7.
• This creates a layered harmonic effect, often described as a “backdoor dominant” sound.

Chromatic Passing Tones and Voice Leading

• Chromatic passing tones are an essential feature, placed not only between the root and flat 7 but throughout the melodic line.
• Voice leading often uses descending chromatic lines that connect chord tones smoothly, enhancing the improvisational flow.

Key Solo Phrases and Concepts to Practice

Triads with Chromatic Approaches

• Practice moving diatonic triads with chromatic neighbor triads.
• This technique adds tension and a modern jazz vocabulary flavor.

Augmented Triads

• Coltrane’s frequent use of augmented triads adds an unexpected brightness and tension.
• Experiment playing augmented triads over dominant chords and resolve them creatively.

Use of Backdoor Dominants

• Playing a minor third above the dominant chord (e.g., C7 over A7) creates “backdoor dominant” sounds.
• This technique expands harmonic possibilities and enriches solo lines.

Secondary Dominants and ii-V Progressions

• Incorporate secondary dominants (V7 of ii or V7 of V) to add harmonic interest.
• Practice common ii-V patterns and how Coltrane navigates them with voice-leading and chromaticism.

Practical Tips for Learning “Locomotion”

Step 1: Learn the Melody and Blues Form

• Sing and play the core motive along with the chord changes.
• Memorize the 12-bar blues structure and the bridge progression.

Step 2: Master the Bass Line

• Begin with the root notes, then add chord tones to outline harmony.
• Understanding the bass movement aids in navigating chord changes during solos.

Step 3: Practice Triads and Chromatic Approaches

• Use diatonic triads of C major and approach them chromatically.
• Experiment with augmented triads and minor 7 related triads.

Step 4: Explore Altered Dominants and Backdoor Dominants

• Practice playing dominant chords a whole step below the target chord.
• Try using flat 9 and sharp 11 tensions judiciously.

Step 5: Improvise with Voice Leading and Chromaticism

• Focus on smooth voice leading with chromatic passing tones.
• Apply these concepts over the bridge and the blues sections.

Conclusion: Unlocking the Genius of Coltrane’s “Locomotion”

John Coltrane’s “Locomotion” offers a masterclass in blending traditional blues with modern jazz harmonic and melodic innovations. By dissecting its form, harmony, and solo techniques, musicians can gain valuable insight into Coltrane’s approach to improvisation.

This piece encourages players to:

• Embrace simplicity in motives while exploring complex harmonic substitutions.
• Use chromaticism creatively to add tension and release.
• Develop a strong command of voice leading and altered dominants.

With dedicated practice of the concepts outlined, you can enrich your jazz vocabulary and bring new life to your own performances.

Frequently Asked Questions

What is the form of “Locomotion” by John Coltrane?

It’s an AABA form with the A sections based on a 12-bar blues and an 8-bar chromatic dominant bridge.

Which scales should I use for soloing on “Locomotion”?

Primarily Mixolydian for dominant chords and Dorian for minor chords, with occasional altered tensions like flat 9 and sharp 11.

How does Coltrane use chromaticism in his solos?

He uses chromatic passing tones and chromatic triad approaches to connect chord tones and add tension.

What are backdoor dominants and how are they used in this piece?

Backdoor dominants are dominant chords a minor third above the actual dominant chord or a whole step below the target chord, used here to add harmonic variety and smooth resolutions.

Embrace these insights and techniques to deepen your mastery of Coltrane’s “Locomotion” and enhance your jazz improvisation skills.

Happy practicing and keep swinging!