The free buzz is the foundation of every brass player’s mechanical understanding of sound creation.
For starters, blow air between the lips, forming the aperture — the small opening where buzzing occurs — air is moving but no sound yet.
…slowly bring lips together (pierce) until a buzz is created. For higher tones, the aperture must be smaller and tighter, for lower notes the aperture must be larger and more relaxed.
If no buzz happens, do not fret! Place the top lip over the bottom lip and attempt a buzz (almost guaranteed).
Once a buzz like this is well practiced, attempt a free buzz while slowly pulling the bottom lip out to the correct position. If the buzz stops, try again! Over time, you will be able to create a proper free buzz.
If you are still having trouble with creating a free buzz, buzz on the mouthpiece and pull the mouthpiece away while maintaining the buzz. This requires vigilant use of a fast air stream. Pulling the mouthpiece will give the student a false sense of security. Make sure to keep the air moving!!!