Tuning the 5th Partial on Brass Instruments

Who

This tuning issue affects all brass instruments: trumpets, trombones, French horns, euphoniums, and tubas. Whether in middle school, high school, or professional bands, players of these instruments face challenges with the 5th partial’s flatness, impacting ensemble intonation.

What

The 5th partial in the harmonic series—such as 4th space E (and Eb and D) on trumpet, above-staff D/Db/C on trombone, A on French horn (F-side, open), or middle D/Db/C on euphonium/tuba—tends to sound flat compared to the equal-tempered scale used in modern music. This flatness, about 14 cents, causes intonation issues in chords or unison lines, disrupting the band’s harmonic blend.

Why

The flatness arises because the natural harmonic series doesn’t align perfectly with equal temperament. The 5th partial, a major third above the 4th partial, is inherently flatter than the tempered major third, making notes like 4th space E on trumpet or above-staff D on trombone sound out of tune without adjustment, as noted in brass pedagogy resources like The Art of Brass Playing.

Where

Corrections are applied through:

• Embouchure: Lipping up raises the pitch.
• Alternate Fingerings: On trumpets, using 1-2 instead of open for 4th space E; on horns, switching to Bb side for high A.
• Slide Adjustments: On trombones, pulling the slide inward for above-staff D; on tubas/euphoniums, pulling tuning slides or using compensating valves.
• Hand Position: On French horns, adjusting hand placement in the bell to raise pitch.

When

Corrections are critical in:

• Chordal Passages: In major triads, the 5th partial often forms the third (e.g., E in a C major chord on trumpet), needing adjustment to avoid sour chords.
• Exposed Lines: In fanfares or hymns, like Holst’s First Suite in Eb, flat 5th partials stand out.
• Unison Sections: In unison brass lines, such as in Sousa marches, flatness disrupts pitch unity.
• Lyrical Solos: In expressive passages, precise intonation enhances tone quality.
• CAUTION: When the 5th partial is a major third in the chord, the 14 cents flat works to your benefit, which we’ll talk about in another post. A major third should be 14 cents flat to be in pure tune, as opposed to equal temperament tuning.

How

To correct the flat 5th partial:

1. Use a Tuner: Identify flat notes (e.g., 4th space E on trumpet, middle D on euphonium) with a chromatic tuner to confirm the issue.
2. Practice with Drones: Match the fundamental pitch (e.g., low Bb on tuba) to train the ear for adjustments.
3. Incorporate Long Tones: Play sustained 5th partial notes, lipping up or adjusting slides to center pitch.
4. Tune Chords Bottom-Up: In rehearsals, adjust the third (often the 5th partial) last to fit the chord, ensuring blend.
5. Use Alternate Fingerings or Slides: For trumpets, try 1-2 for 4th space E or extend first/third valve slides; for trombones, pull the slide inward for above-staff D; for horns, use Bb side or hand adjustments for A; for tubas/euphoniums, use 4th valve (e.g., for middle D) or pull slides.
6. Consult Pitch Charts: Use resources like Norlan Bewley’s charts to map tendencies for each instrument.
7. Practice in Context: Incorporate corrections into scales (e.g., C major for trumpet, Bb major for tuba) and ensemble parts to internalize adjustments.

Conclusion

The flat 5th partial, affecting notes like 4th space E on trumpet, above-staff D on trombone, A on French horn, and middle D/Eb on euphonium/tuba, poses intonation challenges in ensemble settings. By using embouchure adjustments, alternate fingerings, slide pulls, or hand positioning, and reinforcing with tuners and drone practice, players can correct these notes. Directors who teach these techniques empower brass players to achieve precise intonation, enhancing the band’s harmonic clarity in demanding repertoire like fanfares or lyrical passages.