I have seldom been so aesthetically and physically overwhelmed by an exhibition and by an exhibition space as I was while viewing the Metropolitan Museum's new Michael C. Rockefeller Wing here. This is a 42,000-square-foot area devoted to the art of Africa, the Pacific Islands, and Pre-Columbian, and native America. It unites the collection of the former Museum of Primitive Art, founded by Nelson A. Rockefeller in 1954 and donated by him to the Metropolitan Museum in 1978, with the Metropolitan's own holdings in these areas. The new wing was named in honor of Michael Rockefeller, who disappeared in 1961 while on a collecting expedition among the Asmat people of New Guinea.
There are over 1,500 objects on view, including wood, stone, and terra-cotta sculpture, precious and semiprecious stones, gold and silver treasures, and a variety of textiles -- all spannng 3,000 years, three continents, and a large number of islands.
The African section includes about 500 objects from sub-Saharan cultures. Among these are the Western Sudan, the Guinea Coast, Nigeria, Cameroon, Gabon, and Central Africa. Included are classic bronze portrait heads, expressionistic wood masks, doors, houseposts, staffs, stools, ornaments -- and many other household and religious works.
The Pacific Islands are represented by small utensils for daily use, articles of personal adornment, and objects for ritual use. Outstanding here are an elaborate temple drum, a re-creation of a ceremonial house using the painted bark paintings of the Kwoma people of New Guinea, and a 25-foot crocodile effigy also from New Guinea.
Ancient Mexican art from all major periods is included in the section devoted to native American and Pre-Columbian art, as well as everyday and religious objects from as far north as the Arctic regions of Alaska, and as far south as the Andes of Peru.
But all that hardly even begins to tell the tale. It is about as impressive an installation of impressive art as one can hope to find anywhere. My immediate reaction was to decide to remove the word ''primitive'' from my art-critical vocabulary. A great deal of the art on view may differ widely from what we in the West think of as art, but at its best (and much of that is on display here), it is magnificent.
This truly outstanding collection will remain permanently on view in this wing -- although there will be some rotation of individual pieces from time to time 20th-Century French drawings
The Metropolitan is also showing a selection of 20th-century French drawings from its Robert Lehman collection. Of particular interest is a large group of watercolor-and-pencil drawings by Paul Signac. Although most of these are landscape studies, there is one large and impressive still life, as well as an intriguing, smallish pointillist drawing, ''The Dining Room.''
Other works that caught my eye were Suzanne Valadon's charcoal and colored chalk drawing, ''Before the Bath''; a few early studies by Jacques Villon; Matisse's charcoal sketch ''Reflection in a Mirror''; and two excellent Vlaminck drawings in which the ink was applied with a wooden stick.
Andre de Segonzac is represented by a large and powerful watercolor of a still life, and Pierre Laprade by a lovely and very small watercolor entitled ''Landscape in the Pyrenees at Arudy.''
Although it is hardly representative of French 20th-century drawing, this show is an excellent opportunity to become better acquainted with the watercolor drawings of Signac -- as well as with fairly typical examples by other recent French painters.
It will remain on view through March 14. Andrew Wyeth
While walking through the Metropolitan's new American wing, I was stopped cold by Andrew Wyeth's recent tempera ''Night Sleeper,'' which is on anonymous loan to the museum. It is a fairly large painting depicting the painter's dog asleep against a burlap sack in a building through whose windows a gristmill and a stream are visible.
It's a magnificent piece of work on all levels, and reaffirms my belief that Wyeth is one of the very best American painters around -- as well as one of the most maligned. It's worth a trip to the American wing all by itself.