Derived from the mouth harp of the Hmong people,[1] Đàn môi (in Vietnamese: Đàn môi, "lip lute") is the Vietnamese name of a traditional musical instrument widely used in minority ethnic groups in Vietnam (including the Jrai "Rang Leh"[2]). An inward orientated ("the lamella points inwards towards the mouth"[3]) idioglot (noncomposite: "the tongue and frame are of the same piece of material"[4]), mouth harp somewhat similar to the metal heteroglot/compound jaw harp, the dan moi, rather than being held against the teeth while being played, like a jaw harp, is held against the lips while being played.
This gives much more flexibility to the player, leaving them freer to shape their oral cavity as a resonance chamber to amplify the instrument.