I’ve been playing whistle for a while. I’ve been working on flute the last couple months.
I use oxxooo for the first C natural on a D flute. It’s always a little sharp. I think I hear players backing off the wind on this note to flatten it. Is there another way to flatten it?
options, depending on your flute:
oxx xoo
oxx oxx
oxx oox
oxo xxx possibly, though this seems to raise the pitch
Adding to Jim’s list:
OXX OOO (the most common Cnat I’m aware of)
and
OXO OOO (may need to lip down, often used in certain runs in fast tunes)
Eric
What about oxx|xox? I use that one plenty.
Thanks for the posts. What can I do with my lips to flatten the note a little? You mentioned “lip down”?
THANKS!
Common advice will be to roll in. You should really learn to change your embouchure (such as it is) to make the note flatter, though. I cannot tell you how to do this.
This in fact is what I usually do. Just drop your chin toward your neck a bit so you’re blowing more into the embouchure hole; this will flatten the note while keeping it “alive.” It also allows you to vary the pitch of the note; you can achieve an effect similar to the C on the uilleann pipes (which is controlled by veiling the top hole on the chanter; the note starts a bit flat of C and gradually rises in pitch as the piper straightens his or her index finger). If you roll in/lip down and then gradually roll out/lip up, you’ll hear a similar effect.
Or try OXX XOX
Or try really ‘filling up’ the flute. My C is really out of tune when I wimp out on the airstream. Maybe not louder, just a focussed and supported air column, like it’s coming straight up from your toes.
Or it might just be the flute, but that’s doubtful. Check the cork against the maker’s specs, just in case. Cork placement throws lotsa stuff off.
and don’t forget half holing! That gives a nice slidy transition on B - C moves.
So many choices… Actually, I find that I generally experiment within a tune to find the C nat that gives the best pitch in terms of where I’m coming from and where I’m going, and also the best fingering changes. oxo xxx is not always the cleanest tonally, but boy is it useful for fast C - D changes and taps/cuts – just a one finger move!
Where the difference between C & D needs to be clear – as in Sadie at the Back Door – you’ll one of the ones with more fingers up.
There’s a way to flatten a note by sliding your top lip forward. It produces the same effect as Brad’s suggestion - changes the air angle - but instead of moving your chin you can move your lip. It works best if you hold your mouth in the “blowing soup” position to start.
I use this and also Brad’s method, depending on the situation. You can also practice it by holding the back of your hand under your lips without the flute, and roll your lip back and forth, feeling where the air stream moves on your hand.
On Dixon’s OXOXXX works well in both octaves.
Usually oxx xoo sounds best on my plastic M&E, but oxx ooo works too if I’m in a hurry. 
I can get by with oxo ooo if I’m playing by myself, but it sounds too out of tune with anyone else.
Thanks for all your advice!
I play a sweetheart rosewood and OXX OOO makes a C natural in perfect tune - BUT it sounds a bit “fuzzy” - any hints on that? Come to think of it - it COULD be my ear - I should try recording some scales and listen to it… Hmm…
/Brian
Is it true that if the OXX OOO produces an in-tune C-natural, the OOO OOO C# will be a little flat? Anyone know more about this? Like the Sindt, I heard that it’s meant to be 1/2 holed. I wonder if it has a very in-tune C#?
It’s normal for the C# to be flat on simple-system flutes. It’s more noticeable on some flutes than others, and very noticeable when you start going to the larger flutes like Bb.
It’s not really meant to be half-holed – the simple-system classical flutes that are now used for Irish music were originally designed with keys, and the C natural was played with a key, not by cross-fingering. To play the C# in tune you vented the C natural key while you played C sharp.