Recognising badly tuned ocarinas - how to measure the breath curve
Knowing how to measure an ocarina's breath curve will help you understand the different ocarinas you play, and also allows you to recognise badly tuned ocarinas.
In a well made ocarina, the pressure should ramp up gradually between notes, with no sudden and arbitrary changes. The two following graphs exemplify a well tuned breath curve and an (exaggerated) poor one.
The curve is created when an ocarina is made by tuning sequential notes slightly flat, requiring you to raise your pressure to compensate. Directly measuring an ocarina's breath curve requires specialist equipment as the pressures involved are so low.
It is easy to measure the breath curve indirectly by measuring these pitch differences using a chromatic tuner.
- Finger any note.
- Blow as steady as you can, holding the note in tune.
- Without changing your pressure, raise the finger for the next note in sequence. Do not tongue the transition.
- Note down how many cents flat the higher note is at the exact moment you lift your finger.
To measure the breath curve of your whole ocarina, begin at your ocarina's lowest note and check each note sequentially, writing down the note and how flat it falls.
Note that while doing this, It is critical that you do not change your blowing pressure, as that will give you a false reading. Some additional techniques are discussed later in this article.
Understanding your results
Once you have measured the pitch changes across the range of your ocarina, understanding the results is a matter of looking at the difference between sequential values. In a well tuned ocarina, the changes should be about regular across the entire range, like this:
- C: 20
- D: 21
- E: 19
- F: 20
- G: 20
- A: 21
- B: 18
- C: 20
You may notice that the changes increase or decrease gradually between sequential notes, which may be done to shape the breath curve. A gradual reduction towards higher notes for example creates a more linier breath curve, as the base curve is exponential:
- C: 20
- D: 19
- E: 18
- F: 17
- G: 16
- A: 15
- B: 14
- C: 13
Any large irregular changes, such as a sudden pressure increase followed by a decrease, is a tuning error. Large variations between values as in this example is indicative of a badly tuned ocarina:
- C: 20
- D: 0
- E: 40
- F: 60
- G: 10
- A: -10
- B: 50
- C: 10
When is a tuning error a problem?
Whether or not an error is a problem depends on how bad it is:
- 5 to 10 cents is usually tolerable.
- 30 or more will be difficult to compensate for when playing at a moderate tempo.
- Larger errors can be objectively considered bad tuning.
I advise double checking your result as it can be difficult to hold your breath perfectly constant at first. I also recommend taking a few measurements and averaging them.
Do be aware that the exact magnitude of the changes between notes will vary with temperature. That is covered on the page 'How air temperature affects an ocarina's pitch'.
Traps, blowing technique, and the impact of tuners
Subconscious pressure changes
If you have been playing the ocarina for some time, you will have learned to play your ocarina in tune by subconsciously changing your blowing pressure.
These subconscious changes will make it appear that your ocarina has a perfectly flat breath curve (zero cents between notes), when in fact it does not.
Something that can help with this is to use a different blowing technique for measuring than the one you use for playing. For example, ramping your pressure up to the first pitch without tonguing.
Also, pay attention to how it feels in your chest when you are exhaling at different rates. This can help you notice when you are changing your blowing pressure.
You may wander if it is possible to measure a breath curve by increasing your pressure as you would while playing. That does not work, as the human body cannot control blowing pressure deterministically. There is no way to objectively compare two ocarinas doing this.
Using good blowing technique
Using a good blowing technique makes it much easier to blow with consistent pressure, and get accurate measurements of your ocarina's breath curve.
People can breath in two distinct ways, called shallow breathing and diaphragmatic breathing. To get the best possible control you really need to use diaphragmatic breathing, and how to do this is explained on the page 'Blowing an ocarina correctly'.
Using a good tuner
Finally, it is worth noting how the tuner you are using can affect your results. There are three factors:
- Tuners often average pitch over time, a feature called 'needle damping'. Needle damping makes it impossible to get an accurate instantaneous reading, as it smears changes in pitch out over a longer period of time.
- Chromatic tuners do not measure pitch continually, but rather sample it periodically. A tuner with a low sample rate will not show you slight fluctuations in your breath, and thus won't show what is actually happening.
- Most chromatic tuners display cents using an analogue dial instead of a numeric readout. This is not ideal as analogue dials are hard to read quickly.
Thus the characteristics you want in a tuner are:
- High sampling rate.
- low latency.
- Little to no needle damping.
- A numeric cents display in addition to, or instead of, a needle based readout.
Such a tuner makes measuring your ocarina's breath curve far easier. The only tuners I know that meet these requirements are software tuners such as APTuner.