Parallel Sixths: Advanced Choir Harmony Training

Advanced Harmony Training

Once a choir masters parallel thirds, sixths provide the next level of harmonic complexity. The interval spans a wider distance, requiring singers to maintain pitch independence while hearing their relationship across more acoustic space. This develops the listening skills that polyphonic repertoire demands.

Sixths create warmer, fuller texture than thirds. While thirds sound bright and direct, sixths add depth and richness to two-part writing. Renaissance composers favored chains of sixths for their smooth, flowing quality. Contemporary arrangers use them to thicken textures without adding a third or fourth voice part.

The exercise trains singers to hear inverted thirds. Ng glides for worship team head voice help upper voices access the lighter registration that wider intervals often require. A major sixth is an inverted minor third, and vice versa. Understanding this relationship deepens harmonic awareness and helps singers navigate complex voicings in repertoire.

Why Sixths Create Richer Texture

The sixth interval positions voices far enough apart that each retains distinct identity while blending into a unified sound. Thirds can fuse so completely that individual lines disappear. Sixths maintain clarity while adding harmonic color.

This quality makes sixths particularly useful for soprano-alto pairings in upper registers. When sopranos sit high in their range, adding altos a third below can sound cramped. Dropping altos a sixth lower opens up the texture while maintaining harmonic cohesion.

Sixths also provide smoother voice leading in descending passages. Where parallel thirds can sound repetitive, sixths offer more melodic interest in each line while preserving harmonic consistency.

Teaching Parallel Sixths to Choirs

Begin by singing a third, then have the lower voice drop an octave while the upper voice holds steady. This transforms the third into a sixth without requiring singers to learn a new interval from scratch. They feel how the sixth relates to the third they already know.

Move through ascending or descending patterns slowly. Sixths require more precise pitch control than thirds because the voices sit farther apart. Small tuning errors become more audible when the interval widens.

Watch for the lower voice dragging behind rhythmically. The wider leap between pitches can create timing inconsistencies. Both voices must attack and release each pitch simultaneously to maintain ensemble precision.

Soprano/Alto vs. Tenor/Bass Sixths

Soprano-alto sixths typically work best in mid-range. When sopranos push above F5, maintaining a sixth below can force altos into an uncomfortable tessitura. Consider switching to thirds in high passages, reserving sixths for more moderate registers.

Tenor-bass sixths face different challenges. The interval can create muddy texture if both voices sing too low. Keep tenor-bass sixths in a range where both parts maintain clarity, typically between G2 and D4 for the bass line.

Experiment with inverting the pairing. Having altos on top with sopranos a sixth below creates unusual but sometimes useful textures. This inversion works particularly well when sopranos need relief from sustained high singing.

Using Sixths in Repertoire

Listen for opportunities to apply sixths in arranging or improvisation contexts. When adapting three-part repertoire for two voices, sixths often work better than thirds for maintaining harmonic interest. They provide variety without requiring additional vocal parts.

In liturgical settings, parallel sixths work beautifully for descant lines above congregational hymns. The wider interval ensures the descant remains distinct from the melody while adding richness to the overall sound.

Singers who tend to drift flat on descending lines can benefit from descending drone exercises that reveal pitch loss. Study Renaissance polyphony to hear how composers deployed chains of sixths for smooth, flowing textures. Palestrina and Byrd used them extensively, creating harmonic progressions that feel both logical and expressive. Analyzing their voice leading illuminates how sixths function within larger harmonic structures.