What Are Upper Partials?

A note played on a natural acoustic instrument, as opposed to an electronic one, isn't one single note. It's made up of a series of tones called the harmonic series, plus other higher tones. The quality of the sound is determined by the number and relative intensities of these upper partials.

Volume Control vs. Playing Dynamics

• When you turn the volume control on your television up or down, the quality of the sound itself doesn't change.

  • It gets louder or softer, but the quality stays the same.

• It's different when you play more loudly or softly on a string instrument.

  • When you move the bow closer to the bridge, the sound not only gets louder but the quality also changes.

The Role of the Bridge

• The closer to the bridge you play:

  • More audible upper partials are present in the tone.

• The further from the bridge you play:

  • The sound becomes more veiled and sweeter, as the upper partials are less audible.

Player vs. Audience Perception

The crucial point is that what you hear as a player, with the instrument close to your ear, is quite different from the sound that the audience hears from a distance. This occurs because:

• The upper partials in the sound are the first to drop off, while lower partials travel further.

An Example

• A low note played on a large booming horn in a range of hills or mountains:

  • May travel and be heard for several miles.

• A high note played on a piccolo:

  • Would fade out after a far shorter distance.

The Sweet Spot

This means that if you play near to the bridge, where more upper partials are produced, the sound next to your ear may seem edgy. However:

• Because those upper partials don't travel as far as the audience, but drop off before they reach them, the sound the audience hears is mellow and sweet.

The Danger of Too Much Sweetness

The danger is that if you try to produce too mellow and sweet a tone directly under your ear, the result may be misleading.

• In other words, if the sound you hear is actually the exact sound you want somebody many meters away from you to hear, the sound that actually reaches them may end up sounding nothing but too weak.