Smot is a Buddhist chanting style unique to Cambodia. It is highly melismatic and performed by single singers or in group.
Kai Sokmean, a monk at Moni Prosity Vong near Phnom Penh is performing several smot, recorded during a fieldtrip in 2010.
Sara Peahn, a popular smot
Tom Nuhn Savak
Another popular smot is the tree-tune Chey Toeus:
Chey Borb Brokah
Chey Preah Puth
The tonal system of the chanting is closer to Western equal temperament than to a sever-tone equidistant scale known in Cambodia and Thailand, although sometimes it switches between them (see papers below).
An interesting Cambodian instrument in terms of its tuning system is the roneat deik. It is has iron plates instead of bronze
Is appears that its tuning system of the roneat deik is in between a Western equal and a Cambodian seven-tone equidistant tuning. Indeed the instrument is both used for Cambodian music as well as playing along Western classical ensembles.
It seems that the often complex tuning systems of Southeast Asian musical instruments are often compromises between simple tunings (like equal tuning) and other constraints, like problems of instrument building, adjustments to ensembles playing along, which might use differently tunings, and playing techniques (especially with wind instruments). So Southeast Asian tuning systems seems to be temperaments just in the Western sense of compromises between constraints.
Bader, R.: Buddhism, Animism, and Entertainment in Cambodian Melismatic Chanting smot. A. Schneider & A. von Ruschkowski (eds.): Hamburg Yearbook of Musicology 28, 283-305, 2011.
Bader, R.: Temperament in Tuning Systems of Southeast Asia and Ancient India. In: R. Bader (ed.): Computational Phonogram Archiving. Springer Series Current Research in Systematic Musicology, Springer Heidelberg, 2018 (forthcoming).