The Republic of Indonesia, more than 13,000 islands separating the Pacific and Indian Oceans, is culturally more diverse than North and South America combined, with four main religions and 300 ethnic groups. Indonesia's 175 million inhabitants live in rain forests and hot dusty cities, farming villages and touristy towns. Since declaring their independence and unification at the end of World War II, the Indonesians have been assembling a national identity, but they do seem to have one thing in common. There's more art in Indonesia than plastic. Handmade objects and natural materials, live and local entertainments are more a part of Indonesian life than the prefabricated, mass-media bric-a-brac consumed by the rest of the world. A sampling of this stunning diversity will be offered in the United States over the next 18 months by the Festival of Indonesia. It begins tonight with a performance at the Kennedy Center.

Initiated by former Indonesian foreign minister Mochtar Kusuma-Atmadja, the Jakarta-based festival was set up as an independent foundation with government and private funding, to display Indonesian art here on a large scale. Performing groups, art exhibitions and films will represent different geographic areas with both traditional and contemporary art. Some of the best-known Indonesian exports -- Balinese monkey chants and Javanese shadow puppets -- are on the schedule, along with work that has seldom been seen outside Indonesia.

The festival's official opening tonight will preview four of the 12 performing groups headed for the States, with excerpts from the touring programs of the Court Art of Java, the Children of Bali, the Sundanese musicians and dancers, and the Sumatran dancers from Aceh. Tonight's program, given in honor of Indonesia's Foreign Minister Ali Alatas and hosted by the Indonesian ambassador to the United States, Abdul Rachman Ramly, and his wife, will play to 1,600 invited guests, with an additional 1,000 seats available to the public.

"The Court Art of Java" represents Indonesia's most refined classical dance and music. Seeing the program, most Americans would probably identify it with other high art traditions of Asia, like the exquisite court styles of Cambodia and Thailand. Political and social changes over the past 50 years have altered the status of these traditions, sometimes threatening their very existence, but in Java they've had special care.

After independence the Indonesian sultans lost their political power, but they retained symbolic leadership of high-art traditions, especially in Central Java. Surakarta (Solo) and Yogyakarta, situated near important ancient temple sites, preserve their own styles of dance and drama. Artists have close ties to the royal courts as well as to national arts academies in each city.

The rarely seen Yogyanese court dance form Bedhaya (pronounced Bedoyo) will be performed tonight. A solemn and beautiful ritual, Bedhaya was once too sacred to be performed outside the court, and it still represents the ideals of unity and spirituality in an abstract dance form. The nine female dancers first move in symmetrical formation, symbolically joining in communion with the group. In the second section they enact a story with stylized motions of attraction and conflict, once again culminating in a rapprochement. The piece concludes with another group dance.

Dressed in tight-fitting batik sarongs, velvet vests and filigreed crowns, the women travel in slow, introverted gliding motions across the floor. They bend and curve their bodies in an ever-changing cluster of oppositional focuses. Almost exactly contrary to Western ballet dancers, they never confront the audience directly or two-dimensionally. Their bodies always look multifaceted, elusive. Even in their symbolic battles, they will edge up to their opponent and make sudden, deadly jabs with a dagger hidden by silken cords.

Bedhaya, like the other Javanese traditional arts, is a fusion of Islamic philosophy and the older Hindu-Buddhist heritage. Its stories may be based on the Hindu epics Mahabharata or Ramayana, on Muslim texts, on tales of the folk hero Pandji, or even on recent history. Bedhaya is a dance genre, rather than a set work, and the touring version to be presented tonight was set by one of the great masters of Javanese classical choreography, R.W. Sasminta Mardawa (Rama Sas).

The gamelan orchestra accompanying the Court Art program is one of 15 sets of instruments housed at the palace of Yogyakarta. It is made up largely of bronze gongs and metallophones, and makes a mellow, haunting sound that changes subtly through the effects of contrasting instruments like the stringed rehab and a high, nasal female voice. Tonight's program will offer an unusual opportunity to hear three gamelans in sharply contrasting styles. While the classical Javanese ensemble is quiet and meditative, virtually the same instruments, in different combinations and balances, create totally different effects in Sunda, West Java, and in Bali.

Java's tiny neighbor, the island of Bali, did not adopt Islam, which has prevailed in Indonesia since the 15th century. Bali's culture and religion are a blend of Hindu-Buddhist practice and an earlier, animistic belief in a spirit world with very real powers over everyday life. Balinese dance, drama and music are more explosive and colorful, less meditative and dignified than their counterparts in Java, though they share the basic approaches to movement and sound. The Balinese gamelan is brassy, almost raucous in tone, with rapid, interlocking rhythms and frequent excitable punctuations of sound. In both male and female dance styles, the body is more regular, the rhythms are broken with suspenseful holds and sudden starts, the gaze flashes from a swooping, scanning openness to an intense glare.

In Bali, performance and other arts are not a separate practice, but saturate the life of people. From the daily making of offerings to the gods -- at the most modest, a woven palm-leaf tray with a few flowers, some rice and a stick of incense artfully arranged on it -- all Balinese take part in creative life. Children are never excluded, and in some performance forms children are considered ideal executants because of their physical beauty and their lack of self-consciousness. Whenever dancers and musicians practice or perform, tiny heads appear behind the fences and at the sides of the performing space. Youngsters eagerly try out movements; often they begin studying with local teachers or copy their performing parents. The Children of Bali company was assembled for the Festival of Indonesia from talented boys and girls between age 9 and 16 who study in the villages surrounding the city of Denpasar.

Legong is Bali's closest approximation to a court dance style. Perhaps the island's best-known dance, Legong in its ancient form was done by prepubescent girls who went into trances during the performance. Now, removed from its strictly ritual functions, it can be done by older females as well. Like Bedhaya, this dance has its purely abstract and narrative sections. Three girls take all the parts.

The condong, or servant, introduces the dance and later appears as a magic bird in the favorite "Lasem" story. The two other dancers, called legongs, are usually well matched in size and looks and are more refined than the condong. The legongs represent noble characters and act out courtship or competition, often mirroring or closely shadowing each other, while the condong has to be more vivacious and sometimes even fierce in her roles. Contrast and high intensity are characteristics of the Legong style. The dancers continually flicker between darting mobility and serene composure.

Balinese art is rooted in the villages. The exuberant music and dance of Sunda also has folk connections, but now centers on a more urban environment. The tuned metal instruments of the Sundanese gamelan are supplemented with the bamboo angklung and wooden xylophones. Sundanese music is more Middle Eastern sounding than the classical gamelan, with an ornamental melodic line and freer, more emphatic, often syncopated rhythms. The musicians frequently shout responses and encouragement to the featured drummers and singers. Using traditional instruments and techniques in a freer, more improvisational way, they sound Indonesian, but they sound urban too. The Sundanese musicians, together with dancers in the popular Jaipongan style, will give their own performance on Tuesday at the Baird Auditorium, National Museum of Natural History.

Lead singer Idjah Hadijah, who appears with the Sunda instrumental group at the Kennedy Center, is a popular performer in West Java, where her cassettes are in great demand. Unlike a rock singer, she does few physical gyrations; instead, her voice slides and swivels and vibrates with a wide array of seductive coloristic effects. The six-man drumming ensemble Kendang Rampak will play a number in its closely coordinated, pyrotechnic style.

The Saman dancers from Aceh, Sumatra, embody even more strongly the idea of unison. Seated shoulder to shoulder, the 15 men, in two groups with two leaders, chant and slap their bodies in high-energy rhythmic choruses. An amazing choreographic variety is possible within this restricted format, and the group takes on the look of a precision drill team as the dancers accelerate to nearly ecstatic speed. The curling melodic line of their Islamic chants seems to draw their bodies into spirals, vigorous bouncing, and nodding exchanges with their neighbors.

While the Sundanese Kendang Rampah drumming is a recently invented style, Saman is a traditional form found in Southeast Aceh, Sumatra. Created in the 16th century as a religious and teaching practice, it is usually performed at celebrations and festive occasions, when rival villages send their best Saman dance groups into competition.