I was recently asked this question privately and as it seems to crop up here from time to time thought it might be helpful to post my response up - although the questioner was asking regarding flute-playing, the answer/explanation applies to both flute and whistle.
Question:
I got used to playing D second octave with all fingers xxx xxx but a little higher than the first octave. (i.e. overblowing.) Yet, I see most of the flute players playing oxx xxx. Is my fingering wrong and in what way? I’m trying to catch up…
Answer:
As you saw from your observations of other players, yes, oxx xxx is the normal 2nd 8ve D fingering. You can play it with the fundamental (1st 8ve) fingering (xxx xxx) just overblown, and there are times when this may have advantages, either in a complicated passage of finger changes or because you actually want the slightly different timbre this fingering gives the note as a positive thing, a chosen musical effect. However, I would say that both those situations are really for fairly advanced players working on subtleties; beginners/improvers should be working on using the standard fingering and getting as familiar and fluent with it as possible in all contexts by constantly using it and practising it until it becomes automatic, second nature (like a good many other technical challenges in the process of learning any instrument!).
There are good reasons why the standard fingering is oxx xxx. Let’s try to demonstrate why: first, try playing both ways - sustain the best tone you can on the standard fingering oxx xxx and then put L1 on to make xxx xxx - listen to what happens. Then do the opposite. Then play some slow scales “over the break” from 1st to 2nd 8ve and back - again try with both fingerings and hear the difference. Long established general opinion is that the “vented” fingering oxx xxx has a stronger, cleaner, more in-tune sound and offers greater dynamic control (louder/softer without breaking back down to the fundamental). Do you agree?
The reason for this is that, as the 2nd note in the harmonic series, the node in the wave form in the air-column inside the flute/whistle is at or very near the C# tone-hole. By opening the hole you assist the formation of the node (forced by overblowing, which doubles the wave’s frequency) and the definition of the wave at that higher frequency and reduce the element of undertones from the fundamental in the resulting sound. This venting is less necessary in the over-blown 2nd harmonics of the rest of the scale which anyway have less of a tendency to sound undertones (I think because those notes are not based on the full length of the tube - not sure on this point) and for which appropriate vent-holes are not in any case available on a normal flute/whistle. (3rd octave is another story!) That is the gist of the matter. I hope I have described it correctly - I am not an acoustic scientist! You can read about the science of flute acoustics in these articles if you want to know how/why flutes work in the way they do (1st of 5 - they give links to the following ones). Lots of useful things in there that will help you to understand what you are doing or why you are trying to/need to do it.
Simple answer to end: there are very good traditional players who mostly use the same fingering in both octaves, so it isn’t “wrong” in trad music. Classical players would say it is wrong for reasons of clarity and control of tone and dynamics, and you can test for yourself why. There is some risk in using overblown xxx xxx that you won’t hit it cleanly, will get a wolfy sound or drop the octave unintentionally or get a squeak - completely avoided by using oxx xxx. Most players in all genres learn to use the vented fingering most of the time (on whistle too!). I’d advise doing it “right”. A fairly short period of intensive and consistent regular practice will soon make it habitual. After all, every school child learning Bohm flute is expected/made to do so and without exception they all get it!
Response:
Thanks! It can’t be more crystal-clear now!
I made the tests with both fingerings, and I fully agree with you. I’ll stick to the normal one as I need to practice a lot.