1. Airflow: The flutist blows air across a small opening called the embouchure hole, which is located just below the lip plate. This stream of air creates a thin sheet of air called the airstream.
2. Air Splitting: As the airstream hits the edge of the lip plate, it splits into two parts:
- Inner Air Stream: This part of the airstream goes into the flute's body.
- Outer Air Stream: This part of the airstream goes over the lip plate and mixes with the surrounding air.
3. Vortex Creation: The interaction of the inner and outer air streams creates a series of vortices (tiny whirlpools of air) at the edge of the lip plate. These vortices are formed alternately above and below the lip plate.
4. Resonance: The vortices generated by the airstream interact with the resonant frequencies of the flute's body. This causes the air inside the flute to vibrate at specific pitches, producing sound.
5. Sound Amplification: The sound produced inside the flute is amplified as it travels through the instrument's resonating body. The length and shape of the flute's bore (the internal cavity) and the positioning of the tone holes determine the specific pitches and tone qualities that can be produced.
6. Finger Placement: By opening and closing the tone holes along the flute's body, the flutist can alter the length of the vibrating air column, thereby changing the pitch of the sound produced.
It's important to note that the flutist's breath control, embouchure (lip position and airflow), and finger technique all play crucial roles in producing a beautiful and expressive sound on the flute.