Khruang Sai is the string ensembles. A typical Khruang Sai has a treble and alto two string gut fiddles, steel zither, flute, drums, and various symbols. Depending on the size, a three string gut fiddle may be added as well. The hammered dulcimer has become popular and is also used in this ensemble as well as and organ.

The Khruang Sai is used to accompany dances and holidays. It also used in impromtu occasions requiring music. The following is some of the esemble types depeding on the occasion:

Khryang Sai Wong Lek Khryang Sai Khryang Khu Khryang Sai Pi Chawa Khryang Sai Prasom (http://www.seasite.niu.edu/Thai/music/classical/thaiensemble/Khryang_Sai_Ensemble.htm)

Here is the deffinition of the Khruang Sai according to the NIU South East Asia Studies department:

Wong Khryang Sai (Khryang Sai = String ensemble): The String ensemble consists of saw-duang, saw-u, Jakhae, Khlui, and the set of percussion instruments: Ching, Chab, Thone-Ram Mana and Mong. This ensemble is further divided into four kinds in accordance with its size and different instruments as shown above.

Sound clips are available at the website above for all Thai ensembles