Skor thom ស្គរធំ is either a single barrel drum (used in the kong skor or kantoam ming ensemble) or a pair (used in the pin peat orchestra; it is then referred to as skor thom pin peat). Each drum is made from a tree trunk (monoxyle) unlike the large drums of Vietnam and China, which are made like wine casks, with staves. Today the wood used is mainly koki គគីរ and chankiri ចាន់គីរី. In the past there were large jack trees khnor ខ្នុរ but their overexploitation no longer allows the manufacture of skor thom in this species. The diameter of the openings is about 45 cm for a barrel length of about 50 cm.
Concerning the skins: once the animal is skinned (cow, ox or buffalo, formerly wild ox), the skin is immersed in a treatment bath and then dried in the sun. During the drying process, the skin is rubbed with coconut oil to soften it.
The two wet skins are then installed on each opening and then gradually stretched simultaneously using traditional or modern devices (see our image gallery below). First the skins are summarily stretched, then they are left to dry in the sun before being stretched again until the desired sound is obtained; the manufacturer does not hesitate, if necessary, to mount them with joint feet on each of them. It is preferable to wait until the dry season to perform this task because once stretched, the skins will no longer be able to be stretched, except by using wooden wedges inserted under the skin at the nailing level, which is not desirable from an aesthetic point of view. Finally, the skins are nailed with one or two rows of metal or bamboo nails. Some drums remain smooth while others are carved with lotiform patterns well known from the Angkorian period. On the back of the drum, in the center, a carrying ring is inserted before the skins are laid. Between the base of the ring and the shaft, a hemispherical (less commonly conical) piece of wood is placed on top of a piece of serrated leather that is reminiscent of the star that decorates the tympanum of bronze drums.
Before playing, a piece of rice paste, known as bay samphor បាយសំភោរ, litt. "the rice of the drum", is glued to the center of each skin to tune them. Originally, bay samphor was made from ordinary rice that was kneaded into a smooth paste and then mixed with ash; today, musicians commonly use Patafix (blue or green in the Cambodian market). When skor thom is played in pairs, each drum produces a sound of different pitch.
The sound of skor thom represents thunder. It underlines the action of the actors when it accompanies for example the lakhaon theater or the Sbek shadow theater. In the pin peat orchestra, the skor thom and the samphor are placed at the front of the orchestra because the musicians must see the actors or dancers. Depending on the case, skor thom and samphor are struck by one or two musicians. The skor thom is laid out on the ground obliquely, either in a wooden tub (pictured above), or with a device on which each is hung (opposite), or with two bamboos or crossed sticks.
Only one skin per drum is struck with two wooden sticks about 35 cm long. Different strikes are used, each designated by an onomatopoeia :
Ting. Resonant strike on the small or large skin.
Tup. Dry and muffled strike on the middle of the small skin.
Pak or chak. Sharp strike on the edge of the large skin.
Theng. Strong and resonant strike on the large skin.
Theng. Strong and resonant strike on both skins.