Vietnamese operas always have background music. The traditional instruments used on a cheo san dinh stage include the ha and the nhi, two double-stringed instruments: and the scio, a bamboo 'flute. The percussion also plays a major role and includes a small drum (tang con), large drum (tang cai), the horizontal cylinder-like drum (tang cam), gong (thanh la), and the wooden tocsin (no). The small drum helps to maintain both rhythm in song and dance and a dramatic background to the singing. The old saying, "There's no cheo without a drum," proves the importance of the drum in a cheo performance. Instruments such as the nhi, combined with a drum set, can make a perfect orchestra. Good drumming can make up for a weak performance.
In modern cheo, other musical instruments enrich the background music. The sixteen-stringed zither (MO luc), hammer dulcimer (tam MO luc), double-stringed lute (nguyet), and the flute (tieu) add their harmonious influences.