In this article, we will examine how to test for the intonation of a dizi, and discuss which ``base'' key of dizi one should first purchase.
Intonation, or how in-tune the instrument is, is a very important part of selecting a decent dizi. The types of dizi we will be looking at are of the 6-hole variety, tuned according to a diatonic scale starting from the fundamental or tongyin. This is true for all modern made dizi, often identifiable by observing that either tone hole 2 is closer to tone hole 3, or that tone hole 2 is larger than tone hole 3.
Since intonation testing requires actually being able to play the dizi, one may have to peek at some of the later articles first to get a hang of what is required.
Determining ``Base'' Keys
Unlike many other [western] woodwind instruments, dizi come in different ``base'' keys. Traditionally, the ``base'' key of a dizi is identified by the pitch name carved next to tone hole 3 of the dizi, which corresponds to the expected pitch when the dizi is covered at tone holes 4--6.
Another way of denoting the key of the dizi is to label the pitch of the fundamental (or jiyin) below tone hole 1. This style of denoting the key of the dizi is often in conjunction with the pitch labelling at tone hole 3. In case it doesn't, then a dizi with such a labelling will have a ``base'' key that is a perfect fourth lower than what is written, e.g. a ``D'' carved near tone hole 1 means that it is really a dizi with ``base'' key of G.
Knowing the ``base'' key is important because when directions refer to a specific dizi for use in a piece of music, it is the ``base'' key that it is quoting.
Side note 1: If one comes from the classical Western background, the equivalent instrument key definition [by the instrument ``C'' key] can be found as a perfect fifth interval lower than the ``base'' key of the dizi. So, a dizi with ``base'' key of G is a dizi in C using standard Western conventions.
Side note 2: For those who have an Irish flute background (or simple flutes in general), the equivalent instrument key definition is a perfect fourth lower than the ``base'' key of the dizi. So, a dizi with ``base'' key of G is a dizi in D using this convention.
If one does not know how to make a [clean] tone from the dizi, it is highly recommended that it be done before intonation testing begins. As a hint, a tone from the dizi is one that is stable and sounds surprisingly clear with a slight ``buzzing'' feel.
Set the tuner to A4=442Hz.
Start by covering tone holes 4--6 and play a gentle but clean tone. The pitch as indicated on the tuner ought to match that of the ``base'' key of the dizi identified earlier.
Now, cover tone hole 3 as well and play another gentle but clean tone. The resulting pitch should drop by a minor second (or semi-tone).
Covering tone holes 2--6 should yield a pitch a minor third lower than the ``base'' key.
Covering tone holes 1--6 should yield a pitch a perfect fourth lower than the ``base'' key. Take note of this pitch.
Play it back, slowly uncovering each hole in order while keeping all the higher tone hole numbers covered. The result should be a diatonic scale rooted at the pitch obtained from covering tone holes 1--6 (the tongyin or the jiyin).
If both the player and dizi are consistent, the resulting tones should not differ from the true pitch by more than 5 cents in either direction (or 10 cents centred on the true pitch, the standard required for professional dizi playing).
If the player is able, the test can be repeated but with an overblow to resonate the first overtone (or second harmonic). The pitches should register as they were earlier, but they will sound an octave higher.
Now, overblow into the fourth harmonic while keeping tone holes 1--6 covered. That tone, and the one with the tone holes 1 and 4 uncovered ought to come out effortlessly (or as effortless as it gets at the jet pressures of the fourth harmonic).
If the dizi can pass all the described steps with decent accuracy in pitch (remember, within 5 cents of the real pitch as measured by the tuner), and can handle the fourth harmonic tones, that dizi is definitely decent and is worth a second look. Some of the lower-pitched dizi can even overblow (with some effort) into the fifth or sixth harmonic---those are definitely high on the list of good dizi.
For a more definitive test, overblow to the third harmonic and compare it with the equivalent 泛音 or fanyin (you should use the hints from the fingering chart). If they match very well, that dizi is definitely very good, at least with respect to intonation.
If one is a beginner, don't worry if one cannot reach the upper end of the second harmonics and the fourth harmonic. If the dizi is accurate enough for all the other tones so far, it will still be sufficient as a ``starter'' dizi for getting one's chops. But it will definitely be a good idea to upgrade it when one is able.
Intonation is important no matter the base key of the dizi. However, many people tend to ask the same question: which dizi should I buy first?
My recommendations are dependent on the use case of the player. If one is just playing on one's own, then really, there's no hard and fast rule---just pick any dizi whose general range you like.
By statistical coincidence, this will tend to be some form of qudi, or a key from C, D, E. The bangdi and xiaodi family tends to be too shrill for the casual self-jammer, while the dadi tends to be too unwieldy/pricey, at least for the beginning.
If one were to buy a dizi to play in either a Chinese orchestra or a band, then I have very specific recommendations for the keys needed. When one is playing with others, the notion of ``key'' is very important to ensure that everyone plays in tune.
In this scenario, I would immediately recommend that the G bangdi and the D qudi be purchased first.
Subsequently, maybe C qudi, then F bangdi. Those four should be sufficient for most pieces that are often played in a Chinese orchestra, which often has pieces in C, D, F, and G, with a smattering of B♭ somewhere.