# How much does an embouchure's shape affects the ability to produce a note on a flute?

I've already asked a bunch of (more theoretical) questions about the subject, but I'm trying to build a flute — a chromatic flute to be more precise. I don't play the flute or any other woodwind currently.

The aim eventually is to build it from bamboo. Because I'll need to buy more "exotic" bamboo for the final product, I wanted to test the viability of an online tone hole calculator on a plastic tube first. I found only one calculator which allows you to plan holes for an entirely chromatic flute, but it doesn't let you insert (or tell you even) the length of the flute, but rather just the base note ("bell"). So I figured I'll just start with no hole other than the embouchure, see what note it produces, adjust length to an accurate note, and then calculate from that note.

The plastic is way too rigid and thus drilling the embouchure was very difficult. The drill I used is only 5mm, and while at first I thought I'd use sandpaper to increase the diameter to ~10mm, the sandpaper barely takes away material. So I tried to work it around with the drill head, but obviously the final shape became pretty rough.

Anyway, I could barely produce any notes from it. I looked at tutorials about correct air blowing into the embouchure, and the sounds I managed to produce from it were 90% note-less air, 9% screeching overtones (they seemed too high to be the fundamental for this flute's length), and 1% which might have managed to ring out the fundamental.

Is it likely this is mostly because the embouchure didn't follow a correct shape? I tried to find out what the shape should be like, and it seems it might need to have sharp, knife-like edges (the inside edges of the embouchure sanded thinly) so it slices the air in two. Is this correct? Perhaps it doesn't matter THAT much and something else with this beginning-of-a-flute doesn't work?

Depending on the diameter of the tube the optimum embouchure diameter should be about 10-15 mm. The hole can either be circular or slightly oval (with the long axis along the tube). The exact shape is not critical as long as it's symmetrical, but the edges need to be really clean and sharp and the sides should be parallel.
The size of the hole affects the tuning: a smaller hole will make the instrument flatter.

• So if the cuts on the edges weren't accurate it is reasonable it forbade the instrument from producing a clear note? About its circularity, I've been thinking whether a perfect circle would refer to a 2D image of the embouchure from above seeming circular, or does it need to be corrected as the embouchure is on a cylinder? Also, as the calculator for some reason doesn't change any values even though it let's you insert the embouchure's supposed diameter, does its diameter and position affect the flute's scale? On Yamaha's website at least they mention it affects the tuning of the octaves.
– TLSO
Jul 9, 2019 at 21:22
• @TLSO I updated my answer to answer your comment. If the hole is badly cut the sound is going to be bad, but it could also be due to your inexperience on the flute. The tuning of the octaves is affected mainly by the position of the head joint cork and not so much by the embouchure. Jul 9, 2019 at 21:33
• The cork's position in effect lengthens the flute's length and thus the air columns, but I think what Yamaha referred to was the overtones' accuracy, as they say "especially in the third octave". Perhaps it does affect this? You also added the if the hole is too small it would make the instrument flat. I know that would be true for the tone holes (if you don't correct by moving them farther from the flute's end), but are you certain it's true for the embouchure? You cited a preferred diameter range from 10-15, so it doesn't seem to be of a very specific value.
– TLSO
Jul 9, 2019 at 21:48
• @TLSO As I said, it depends on the tube diameter. For an inside diameter of 15mm then an embouchure of abut 10mm would be good. For 25mm diameter then 15mm would be good. And yes I'm certain that the smaller the embouchure the lower the pitch. You can test this by rolling the instrument towards you as you blow: the pitch will drop as you cover more of the hole with your lips. Don't worry about the third octave until you have the first two working. Jul 9, 2019 at 22:00
• I don't have the first note working, lol. But it means then that it also varies according to playing technique, so perhaps one should be able to learn to play in tune with his specific instrument, but it's not so that there's a very specific value expected for the constructed embouchure. But what would you do if the bore is conical (and thus not of consistent diameter)? I've been thinking of making something more like a sax perhaps, with a reed. Then it wouldn't have an embouchure like the flute's, but I still wonder how it applies to a flute-like instrument.
– TLSO
Jul 9, 2019 at 22:26