The gumleaf is a wind instrument (or aerophone) that comes with a steep learning curve. Beginners struggle to make any sound at all, and due to the essential oils characteristic of eucalypts, leafists experience a strong taste of resin after blowing just a few notes.

Held against the lips with the fingers, the gumleaf acts as a vibrating valve when blown.

Leaf technique varies: either flat or folded, placed firmly against the lower lip and lightly against the upper lip—or the reverse, stretched between one or both hands (some virtuosos have even crafted a “no-hands” technique, allowing them to simultaneously play another instrument).

Notes can be muted (by cupping the hands), bent, or trilled. A glide from one note to another is possible, as are pulsating, warbling, and “wah-wah” effects.
theconversation.com/amp/art-of-the-gumleaf-gumbaynggirr-elder-roseina-boston-turns-80-37794


https://www.youtube.com/watch?v=0mZ11pA1oKE