"Igbo Arts: Community and Cosmos," an exhibition of more than 100 objects opening today at the National Museum of African Art, offers a splendid opportunity to examine in some depth the prolific artistic production of a single, though large and variegated, West African ethnic group.

In this it differs significantly from the more typical, more generalized exhibition of African art, such as "African Masterpieces From the Muse'e de l'Homme," which occupied the same galleries last spring.

Both types of exhibit make the same large point -- across centuries the various peoples of western Africa created one of the world's more enthralling, inventive, fecund and meaningful traditions of religious art. But the Igbo exhibition, more focused, brings us closer to the art itself and to its religious and social purposes.

Igboland comprises an area of about 100 square miles in eastern Nigeria, a terrain that 15 years ago played an important part in the unsuccessful civil war for Biafran independence. Today this once heavily forested area, populated by some 10 million Igbo, is covered with farms for the cultivation of yams, cassava, maize and other crops. It also possesses superhighways and cities with big buildings, broad boulevards, government complexes, universities and other signs of a changing, modernizing country.

The exhibition, devoted primarily to objects made in the late 19th and first half of the 20th centuries, does not deal in any systematic way with what went before or what came after. But just how ancient the Igbo artistic tradition may be is suggested in the catalogue essay. Herbert M. Cole of the University of California and Nigerian art historian Chike C. Aniakor discuss rich, thousand-year-old archeological finds identified with the Igbo-Ukwu culture. The fascinating way in which older institutions and art-making traditions are blended today with the new is suggested in an 11-minute slide show. It is narrated by a contemporary villager who has just been elevated to high position in a status-conferring society (the Ozo) that may, in fact, date back a millennium to the heyday of the Igbo-Ukwu.

What we see, in other words, are artifacts of a culture caught at a creative high point and poised delicately on the brink of major change. The exhibition is divided into three sections -- art and the individual, art and the family, art and the community -- a device that emphasizes the pervasiveness and interdependence of art at all levels of Igbo society.

If I have a major negative criticism of the show, it is that the materials are given a static, though handsome, presentation. The pieces are displayed in isolated splendor so we can appreciate their exceptional qualities as individual carvings without, necessarily, understanding that they were almost always created as parts of larger wholes. The slide show, a few text panels and a single, riveting mural-sized photo of four male dancers in "maiden spirit" regalia are the only concessions made to cultural context.

The beautiful polychrome full-figure carving of a female figure holding an infant, for instance, originally was part of an impressive grouping of such figures deployed for ritual effect in a men's meeting house. Similarly, each of the many wondrous masks was designed to be worn in spectacular masquerade dances (not, of course, mere spectacles) that, as Nigerian novelist Chinua Achebe points out in the catalogue, subsume "not only dance but all other art forms -- sculpture, music, painting, drama, costumery, even architecture . . . "

(There will be, however, a full program of lectures, tours and workshops with the exhibit, and visitors are advised to take advantage of events that contribute greatly to a more comprehensive understanding of the Igbo and their art.)

What prodigious carvers were the Igbo! The mostly unnamed artists in this show invariably were able to take a single sculptural type -- white-faced (for otherworldly) maiden spirit masks, fierce Ogbodo Enyi (spirit elephant) masks, male status objects (ikenga), figural door posts, or status-bearing stools -- and make from it something powerfully fresh. No two pieces of the same type are ever the same in form or detail, and yet each, because it represents a specific philosophical idea or social function (often both at the same time), is clearly identifiable, even to the uninitiated eye.

Each ikenga, to cite a specific case, depicts a male figure with horn headdress. Each was given to an individual man who had attained worldly success, as shown in the size of his family, the productiveness of his yam crop, his "moral determination and physical strength," and his right to "an honored place among prosperous and respected ancestors." To be presented with a magnificent ikenga, in other words, is at once to have one's worldly achievement and authority confirmed and to be awarded special place in the always-watching eyes of revered ancestors.

And yet the variety of ikenga is great, even in the small selection in this show. In one, for instance, the ram horns (signifying aggression, strength, determination, stoicism) lead into a swirling arrangement of animals atop the head that is as impossible to describe as it is fascinating to regard.

In another the body seems built up of a sequence of status stools, as if the person receiving the object were thus doubly honored (receiving, as it were, two objects in one). In another the ram horns are surmounted by a plate-like headdress adorned with tiny ancestor heads. In another, the rigid vertical body is armless and decorated with myriad scarifications, as if the erectness of the posture were sufficient in itself to compensate for the absence of limbs.

The expressive power and formal variety of Igbo art, like that of so many West African tribes, is so startling and so grand that it does indeed reach across cultures. The somewhat ironical contribution of exhibitions such as "Igbo Arts" is that to focus on the accomplishments of one group is to gain an even greater respect for the African achievement as a whole.

The exhibition, organized by the Museum of Cultural History at the University of California in Los Angeles, continues through Oct. 13. Information on the extensive list of educational programs may be obtained in a free folder available at the museum, 318 A St. NW, or by telephone (287-3490).