Range?

Range is a thing, but range isn't everything. I speak, of course, about the range (or ambitus) of a musical instrument.

I play the dizi, and it has roughly 2.4 octaves of range (including the high instrument G). I also play the concert flute, and that one has about 3 octaves of range. The xun has roughly 1.4 octaves of range, and the bawu has about 2 octaves of range.

Despite all these differing ranges, there are several properties that are unobvious about them.

1. Range must also be specified with key for completeness: the xun for example can only maintain its 1.4 octaves within 2 keys;
2. Range says nothing about innate expressivity even with the key provided: while the concert flute can play ``every'' note in its range (assuming 12-TET), it is significantly less expressive compared to the xun;
3. Timbre across the different registers (or harmonic mode of the vibrating air column of the pipe we are deriving pitches of) imply that the same instrument can sound very differently across its range: the concert flute is brilliant and metallic in its highest registers, and can sound more sombre and mellow in the lowest;
4. Relatedly, dynamics can also be affected by the register, which in turn determines the range.

The thing is, if we are limiting ourselves to the aesthetics of pre-modern music instruments, then all these considerations are more important than just the range itself, but I am jumping the gun here. Let me proceed step by step.

Near the beginning, music was largely modal in nature. This meant that after knowing what the series of notes in a scale are to be used, the piece of music (defined as a sequence of these notes with associated relative durations) can be written choosing any of the notes in the scale as the tonal centre, i.e. the pitch that the sequence of notes in the music that tends to ``return to'' each time. For the wind instrument family, this is where all the simple systems occur---they tend to have anything between 6 to 8 holes, with each successive uncovering of the lowest hole [in the lowest register] raising the pitch exactly to the next note in the series of the scale.

Eventually modal music evolved into modulated music, where instead of using the same notes in the scale but changing the tonal centre, they kept the same interval relationships of the frequencies of the notes used in the scale, but shifted the entire scale up/down by various ratios. Suddenly the same wind instrument may need to play a note that was not a part of the original design as part of the modulated scale---this brings in the concept of ``colouring'' the existing tuned holes to form the so-called chromatic notes (or accidentals). Given the same tuned range of the wind instrument, this meant that each note as played in the 12-TET (or any 12-tone system for that matter) outside of the tuned holes had its own ``character''; additionally, the modulation can hit various limits on the upper end of the range or the lower end, the former problem leading towards a solution of attempting to extend the range of the instrument, and the latter problem leading towards the creation of the instrument's larger cousins.

Notes with their own colour was not a problem for the most part, since the order of the day was usually that of a small chamber group playing. However, as the pieces started to get more complex and large, with the formalisation of what constitutes an orchestra coming into place, the interplay of all these instruments demanded that some level of uniformity of all chromatic notes (at least within the octave, and at best throughout the entire ambitus of the instrument) was to be present. In the brass instrument land, they started adding valves to extend any particular blown harmonic by one, two, or three semi-tones, and sometimes adding an extra horn; wind instruments started having keywork added together with extra holes to vent for the chromatic keys, as well as additional ``register'' holes/keys to force anti-nodes within the air column to coerce the standing waves to jump to the higher harmonic necessary for the extended range.

The existence of keywork discretises the air column within the wind instrument, which vastly reduces its expressivity. This is particularly true for the concert flute, one of the most dramatically different instrument as compared to its predecessor in terms of functional acoustics. While it can definitely play the 12-tones precisely, it lost a lot of techniques that involve playing with the amount of venting of the holes themselves, the way that dizi, xun or even the recorder/traverso can. It also has a built-in compromise in its acoustics, sacrificing a little bit of pitch accuracy in the lowest register to assure working upper register to fit the playing ambitus expected of it in an orchestral setting.

Expressivity is about the number of control surfaces available, and not the ambitus of the instrument. For a harmony instrument, expressivity isn't that important---range is, since there is a need to play the correctly pitched note in its right octave to achieve the ``columnar'' stack of sound expected in its harmony role. That required accuracy is also one of the spurring points of extending the range of the instruments and giving it less guess-work in terms of what note it is playing. For a solo instrument though, being expressive is its main purpose, and so have a larger number of control surfaces is preferable. That is also why we don't see the use of the xun or bawu as being a part of the harmony---it is a horrible joke at best, and masochism at worst.

Range is still a thing though, since it allows itself to be sliced up into different segments to constrain a melody, thus allowing an in-scale kind of modulation that is not available to small-ranged instruments, solo-class or not. It does make a piece of music more exciting, but at the end of the day, the instrument is as it is rightly named: merely a tool for the musician to express whatever he/she wants to do so. Personally, I'm used to the 2+ octave range as a default, since it does allow quite a fair bit of modulation, with the caveat that one may not get ``nice'' concert keys from the ``nice'' instrument-keys (like F-major, G-major, C-major, D-major) to play.

That challenge is why I simply adore playing wind instruments over others, and I don't think anything will change that.