For more than a decade, Karl Ahrens has dedicated his time and creativity to crafting concert quality ocarinas. One of his greatest joys is introducing musicians to the unique properties and haunting sound of this instrument he has come to love.
“Ocarinas fall into the category known as vessel flutes,” Karl explains. They are characterized by a vessel dotted with four to twelve or more toneholes. "
How an Ocarina Works
Karl describes the principles that produce sound in this type of woodwind:
- “First, a player blows through a windway, and that windway focuses air onto a fipple edge, or lip.
- The lip splits the player’s airstream into two parts.
- As the airstream flows over and under the lip, changes in air pressure cause the airstream to start oscillating above and below the lip, creating what is called an edgetone. (The edgetone, like the spark needed to start a fire, is the initial vibration or oscillation of air which will allow an ocarina to speak clearly if that edgetone is properly reinforced by the ocarina’s sound chamber.)
- Next, as the ocarina player’s airstream flows into the sound chamber, the air pressure in the chamber momentarily rises.
- This brief rise in air pressure forces air back out of the chamber through any available openings.
- When air rushes out of the sound chamber, a bit “too much” air leaves, creating a vacuum in the chamber. In other words, air pressure inside the chamber is momentarily lower than the air pressure immediately outside the chamber.
- This vacuum sucks air back into the chamber again, which instantly becomes pressurized, forcing air out, creating a vacuum which sucks air in, and so on.
- The rapid pressurizing and depressurizing of the chamber repeats itself over and over. The rate, or frequency, at which air cycles in and out of the chamber determines the frequency of the ocarina’s pitch. A higher frequency translates to higher pitch. Those air pulses hit our ear drums, which convert them to sound.
Players can change the ocarina's pitch by covering and uncovering toneholes. “If you want to play lower notes on an ocarina," Karl says, "cover more toneholes with your fingers. Fewer openings will force air to enter and exit the chamber more slowly, at a lower frequency. To play higher notes, lift your fingers off some toneholes. This will permit air to flow in and out of the chamber more quickly.
An ocarina maker also determines the instrument's pitch when he fashions its chamber. "A bigger sound chamber produces notes or tones that are lower in pitch than a similar but smaller sound chamber," Karl explains. "This is because air moves more slowly in and out of a larger chamber than it does a smaller chamber, so tones are of a lower frequency.”
Vessel Flutes vs. Elongated Flutes
“The inner chamber of an ocarina can be made in many shapes,” Karl explains. Ocarinas differ from traditional tube-like members of the flute family in that their inner chamber is enclosed, allowing air to exit only through the voicing (or fipple window) and any open toneholes.
“In comparison to a tubular flute, a vessel flute’s enclosed chamber is shorter and wider. Similar to a Helmholtz resonator or to a pan flute, ocarinas produce a pure tone with very few overtones. Tubular flutes, which are essentially open at both ends, produce a lot more overtones for a somewhat different sound.”
“On a traditional flute,” Karl says, “precise placement of tone holes has everything to do with tuning. If a tonehole is placed too far up the tube, the note will sound sharp. If the tonehole is too far down the tube, the note will sound flat.”
Because the ocarina operates on the principles descried above, ocarina makers have more freedom on where they will position the toneholes. “The placement of toneholes doesn’t affect pitch as much as the size of the chamber, the size of the voicing, and how quickly air can move in and out of the open tone holes,” Karl remarks.
“In general, a smaller tonehole produces a lower pitch, and a bigger tonehole produces a higher pitch, although a tonehole’s depth also effects how quickly a chamber can evacuate. A deeper tonehole creates more air resistance, more friction, so it reduces the frequency. I’m simplifying here, but my point is that, unlike with a tubular flute, I could put a tonehole in several different places on an ocarina and get the same pitch.”
Sweet Potato Ocarinas and Other Popular Designs
Since the ocarina isn’t limited to the form of a long tube, and liberty can be taken in the placement of its toneholes, craftsmen have let their creativity lead for thousands of years. Many clay ocarinas have been fashioned to resemble animals and other decorative shapes.
The sweet potato ocarina, probably the most popular design, is easily recognized by its goose-neck windway and egg-shaped body played to the side like a concert flute. Karl’s inline ocarinas are roughly boat shaped and are played like a recorder as opposed to a flute. Though these vessel flutes differ widely in appearance, they all produce their distinctive tones as air is compelled to oscillate in and out of an enclosed chamber.
Now that musicians understand the inner workings of these woodwinds, they may also be interested to check out a history of the ocarina, a review of Karl Ahrens’ Mountain Ocarinas and a profile of his story as an ocarina maker.
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