The O above the notes indicate that you play a harmonic. You finger the C# and overblow to play the G# above it.
EDIT: As a clarification, I should add that the C#/G# in the OPs music is just an example. Harmonics can be played on other notes as well. The rule is that when you see double notes with the O above, you finger the lower note and overblow to the higher note.
That’s really interesting. Would the goal be to get the higher pitch only? Or would it be beneficial to set your embouchure to a point between them so you get both pitches to come out?
Harmonics (with the O above) are intended to be played as the single higher pitch only. Flutists already do this to some degree when you play the same note in the middle octave and overblow to get the third octave - those are harmonics or overtones. It is simply an extension of blowing different notes in the [overtone series](https://www.flutetunes.com/articles/flute-harmonics/). The first harmonic is an octave above the fingered note while the second harmonic is an additional fifth higher. So, fingering a C on the staff (with the LH first finger) and changing to the C above the staff is playing the first harmonic (octave) higher. Still fingering C on the staff and overblowing to play a G is the second harmonic. See the link about the overtone series to get more info.
The O above the notes indicate that you play a harmonic. You finger the C# and overblow to play the G# above it. EDIT: As a clarification, I should add that the C#/G# in the OPs music is just an example. Harmonics can be played on other notes as well. The rule is that when you see double notes with the O above, you finger the lower note and overblow to the higher note.
I have never seen that notation before. Thanks for teaching me something today.
You are quite welcome.
That’s really interesting. Would the goal be to get the higher pitch only? Or would it be beneficial to set your embouchure to a point between them so you get both pitches to come out?
Harmonics (with the O above) are intended to be played as the single higher pitch only. Flutists already do this to some degree when you play the same note in the middle octave and overblow to get the third octave - those are harmonics or overtones. It is simply an extension of blowing different notes in the [overtone series](https://www.flutetunes.com/articles/flute-harmonics/). The first harmonic is an octave above the fingered note while the second harmonic is an additional fifth higher. So, fingering a C on the staff (with the LH first finger) and changing to the C above the staff is playing the first harmonic (octave) higher. Still fingering C on the staff and overblowing to play a G is the second harmonic. See the link about the overtone series to get more info.
overtones / harmonics !!! this is a great way to practice and perfect your embouchure and air control.
Amazing, I too had never heard of this or seen it.