BANGKOK — Sleep like dogs, eat like pigs, dress like angels.

This, in their own words, is the life of an itinerant Chinese opera singer. They are the Gypsies of Bangkok, hauling their stages, their costumes, their musical instruments, their hammocks and their cooking gear through the back streets of the city from one Chinese temple to the next.

They appear, in flamboyant costumes from another age, on dark alleys far from the city’s modern development, and once they have set up their stages, the streets echo with the clash of cymbals and gongs, the energetic beat of drums, and the extraordinary high-pitched screeches and squeals of Chinese opera.

These are the dwindling artifacts of a bygone life, before malls and multiplexes drew their audiences away, performing for a shrinking following of increasingly elderly ethnic Chinese Thais. But the size of the crowd is not important, the singers say. They perform on a higher plane.

“Someday there will be no one left to watch,” said Boonchu Chua, 53, the manager of a troupe. “That’s disappointing, but we aren’t playing for the audience. We play for the gods.” At every performance, the troupe pays homage to the spirits of the local temple.