Playing ocarinas in tune in warm or cold environments

As was mentioned in the article 'Playing the ocarina in tune', the pitch of an ocarina varies with pressure. We learn to play in tune by memorising the pressures required, but there are a few more details that come into play in warmer or colder environments.

Like all wind instruments, the pitch of an ocarina varies with temperature. The voicing mixes your warm breath with ambient air, and the internal temperature stabilises between the two. Thus, the pitch will get sharper as the ambient temperature rises.

You can compensate for this by varying your blowing pressure, but there is a catch: the high notes of a given chamber are far less sensitive to pressure changes than the low notes.

Due to this, the shape of the breath curve required to play at a given pitch standard changes with temperature. If you play in a colder environment, you have to blow proportionally harder on the high notes to maintain the same intonation over the instrument's range.

In the following graph:

• Curve B represents the breath curve of a hypothetical ocarina at its original tuning temperature, such as 20C.
• The steeper curve C represents playing in a colder environment and blowing the high notes up to pitch.
• Finally, curve A represents playing in a warmer environment and cutting pressure.

To reliably play in tune in different situations, you need to learn how the pressure curve of your ocarina changes so that you can target your pressure in the right ballpark. From there, small corrections can be made by ear with relative pitch, or absolute (perfect) pitch if you have it.

Fortunately, practising this is straightforward. Compensating for temperature results in the same breath curves you get by deliberately playing sharp or flat.

Practise method

• First, choose one ocarina of reputable quality that you're happy to stick with for a while. This matters as the breath curves of different ocarinas vary quite a bit, and dealing with multiple breath curves will confuse things.
• Spend a few minutes just blowing the ocarina so that it's internal temperature stabilises.
• Using a chromatic tuner, play a scale in tune from your ocarina's lowest note up to its highest, and notice the pressure curve required. Play through some songs a few times until you become comfortable playing in tune at that pitch.
• Next, play through the same songs but lower the pitch so that all notes are 20 cents flat on the tuner. You'll notice that the high end of the breath curve 'sags'.
• And repeat the same thing, but this time, raise the pitch so that all notes are 20 cents sharp on a tuner. You'll notice a pressure spike in the high end of the breath curve.
• Once these get easy, try playing in tune, with your pitch even flatter and sharper. How many cents low or high can you blow the pitch before the high notes sound airy or screech?

While working on these, you may find it helpful to use a tuner that lets you offset the pitch readings, so they will read zero when you are playing flat or sharp of concert pitch.

The goal is to reach a point where you can jump between the different compensation levels seamlessly. So when you perform, you can just blow the ocarina to warm it, and then work out the pressure you need to use by playing a few notes using a tuner, or by listening to your pitch in relation to your accompaniment.

Temperature compensation and multichamber ocarinas

Like single chamber ocarinas, multichambers are tuned to play at a certain temperature when they are made. Typically, they are tuned so that the lowest note on the second chamber plays at a similar pressure to the highest note on the first.

When you start compensating for temperature, the pressure curve of each chamber responds as has been discussed, spiking when blown harder, and sagging when underblown, leaving pressure jumps between the chambers.

It is not a huge problem, just something that one needs to be aware of. The intricacies of how a given multichamber ocarina behaves can be internalised using the same approach discussed for single chambered ocarinas.

How much temperature compensation is available?

You probably noticed during the previous exercise that the pitch of the low notes can be bent much more than the high notes without having a big negative effect on tone quality. Consequently, the amount of compensation available is limited by the high notes:

• At higher pressures, they will sound harsh or squeak.
• At low pressures, they will sound too airy.

So there is a 'window' within which an ocarina will sound good.

To the extent that I have been able to measure it, an ocarina's pitch changes at about 0.9 cents per degree Celsius. Humidity, like temperature, also has an effect, and the pitch will be lower in more humid environments. I do not know what effect this has in practice, as I do not have a sufficiently controlled environment to measure it.

It is important to have some headroom above and below the pressure curve needed to play in tune so that you can use vibrato, breath pitch slides, and other breath-based note shaping.

You may also find that if you need to blow an ocarina very hard, it is difficult to play at high tempo due to the steep breath curve and large pressure difference between the high and low notes.

Because of these factors, I have found the practical temperature compensation ranges from:

• +/- 5 or so degrees (5 to 10 cents) for very fast complex music,
• to possibly +/- 20 degrees (30 cents) for less demanding music,

The extent to which it is possible to compensate does vary between ocarinas, depending on:

• How the ocarina was tuned. If an ocarina is already tuned to play at high pressure, it will require a lot more effort to compensate for temperatures colder than it was tuned to play in.
• Total chamber volume. Larger ocarinas are more dependent on ambient temperature, as they are less influenced by breath warming. They have more thermal mass and more surface area to lose energy.
• Hole count. As more holes are added to a single chamber of an ocarina, the higher notes of that chamber become less sensitive to pressure changes and, consequently, there is less compensation available.

All in all, I'd strongly advise finding an ocarina tuned to play at a temperature around the average of the situations in which you intend to play it.

Dealing with extreme temperature compensations

Should you have to play in a situation where temperature pushes your instrument outside its optimal range, there are a few options.

• You may just allow your pitch to drift flat or sharp of concert pitch. This is absolutely no problem if you're playing alone, and if you're playing with accompaniment, some instruments can be retuned to you. Recorded backing tracks can have their pitch adjusted using a digital audio workstation.
• Should you only need to play for a short time, warming the ocarina in front of a heater or putting it in the fridge could work. The ceramic body has notable thermal mass and will transfer this stored energy to the air inside the instrument, raising/lowering its pitch.
• It is technically possible to increase the pressure required on the high notes in very hot environments by leaving your fingers closer to the holes than normal. This shades the hole and requires more pressure to attain the same pitch.

But if you regularly need to play in different temperature extremes, it may be worthwhile getting ocarinas tuned to play in those temperatures. Tuneable ocarinas do also exist, although are rare. They have a plunger that can be moved into or out of the chamber, altering its internal volume and thus altering the pitch of the instrument.

Note that moving the plunger in a tuneable ocarina mostly affects the pitch of the high notes, and does not have much effect on the low notes. This is due to the non-linear effect of temperature on the breath curve, and tuneable ocarinas exist mostly to reduce the large pressure changes that would otherwise be required on the high notes.