The lau (Khmer: ឡោ) is a Cambodian flat-faced gong, measuring approximately 25 centimeters across, used in Bassac theater for scenes requiring a loud instrument, such as battle scenes.[1] It is also used to signal the entrance and exit of important characters.[1][2]
The Lau is similar in shape to the Kong chmol which is also used in the Bassac theater.[2] The instrument is large enough that it is hung on a frame, attached by a rope that goes through two holes in the instrument's edge.[1] It is played with a wooden mallet, at a more sedate rate than percussion such as the chhing or pann.[1] "While the Lau is struck once, the Chhing and Pann are struck twice."[1]