As the prevailing tastes in art and architecture change, so do museums. In its 137-year history, the Metropolitan Museum of Art has continually redetermined the presentation of its collection. It is our good fortune that 2007 will be remembered as a time of significant change at the Met — and those changes are all to the good. It has been, as the museum’s director Philippe de Montebello said, the museum’s “annus mirabilis.”

In an extraordinary feat of architectural legerdemain — without the addition of new wings — the Met has reconfigured and increased its gallery space. The first space to be renovated was the Greek and Roman Galleries, which was opened in April. Next was the Joyce and Robert Menschel Hall for Modern Photography, in September, and in October, the Ruth and Harold D. Uris Center for Education and the Wrightsman Galleries for French Decorative Arts. The Galleries for Oceanic Art and the Gallery for the Art of Native North America opened together in November, and finally, this month, the Galleries for 19th- and Early 20th-Century European Paintings and Sculpture.

In accomplishing all of this, the minds behind the Met have enhanced the quality of the architecture and the building’s relationship to the surrounding urban and park environments. The ultimate result of it all is that the magical quality of the light, both from natural sources and the illusionary effects of artificial light, has lent familiar works renewed luster. A walk through this museum today is, in some ways, a completely new way of seeing old friends.

In preserving art and artifacts of the past and present, museums record history through objects that also tell individual stories. I discovered this human element particularly as I traveled through the Greek and Roman Galleries and those devoted to Oceanic Art, which seem more open to the visitor experience. Though the number of objects on view has been greatly increased, I found clean, pared-down displays that balance large and small objects in appropriately designed cases or hangings.

Mr. de Montebello described this process of “making the galleries coherent, lucid, spacious yet intimate” as a result of both “imagination and determination.” He believes that a public institution such as the Met has the obligation to place as much of its collection as possible on permanent view. “But also moving around the objects in the newly installed galleries,” he added, “effects new ideas and new connections.”

In the Greek and Roman Galleries, the concentration of marble sculpture gains immeasurably from the natural light that streams through an elevated central skylight and also creates shadows that help articulate form. I could have been standing in the peristyle of a Roman villa surrounded by a colonnade and a family’s collection of marble busts. Walking through the perimeter galleries, with their newly uncovered windows, I admired the glitter and gleam of precious objects as well as restful views of Fifth Avenue. Old favorites revisited included: the frescoes of gardens and fantasy architectural vistas from the bedroom at Boscoreale, formerly in the Met’s main hall, and the sarcophagus with the touching sculpture of a husband embracing his wife.

Walking into the shed-like glass and limestone hall that houses the Galleries for Oceanic Art, I was immediately struck by the new shades that eliminate harmful rays but expose a shadowy view of trees in Central Park and scudding clouds above. The central partition that once served as backdrop for the ancestor poles collected by Michael C. Rockefeller has been removed, thus admitting more light. Without destroying the effect of the glass wall, a new cantilevered ceiling has been installed, and mounted to it is a ceiling of a ceremonial house from New Guinea that hovers dome-like over the exhibition area. I crooked my neck a long time looking up at its 270 mythical paintings on bark-like palm leaves, each by a Kwoma artist.

New displays of rare textiles from Island Southeast Asia in these galleries contribute to the balance of objects on view between men as carvers and women as weavers. At the end of these showcases, in the new inner Gallery for the Art of Native North America, organized by region, I could not help overhearing one collector say to another wistfully,

“Someday we’ll find one of those.” I stopped to look and learn from their appreciation of an 1850s red-and-black dance robe with shell button borders from British Columbia.

The cantilevered ceiling over the Galleries for Oceanic Art provides new floor space above for 10 additional rooms in the Galleries for 19th- and Early 20th-Century European Paintings and Sculpture. Once through the threshold of the gallery, I felt like I was in a museum within a museum, a vast suite of rooms, each scaled to normal size with baseboards, wainscoting, cornices, and coved ceilings, but in palettes that change according to the mood of the paintings.

“We are telling new stories through vistas,” associate curator Rebecca A. Rabinow said of the arrangement. Beyond the big hits, I noted work in one room by American artists abroad featuring John Singer Sargent’s “Madame X” along with portraits by Whistler and Eakins and, in the next gallery, one by Manet (in his Velásquez moment). Wherever I looked beyond each room, I was drawn to a related work.

I have always found irresistible the transporting experience of the Met’s sumptuous period rooms, the latest of which — the Wisteria Dining Room — is enclosed in these European galleries after being in storage for 41 years. The only Art Nouveau room in an American museum, it was created in 1910–14 by Lucien Lévy-Dhurmer for a Parisian apartment near the Eiffel Tower. With its wisteria theme carried through in every detail of woodwork, metalwork, and wall paintings dripping with vines, for me it rivals in enchantment the unified decor of Whistler’s 1876–77 Peacock Room (also a dining room) at the Freer Gallery of Art in Washington.

I was equally carried away by the renovated suite of 18th-century rooms in the Wrightsman Galleries for French Decorative Arts. The 2004 exhibition “Dangerous Liaisons” brought these galleries to life with a mélange of fashion and furniture and encouraged the curators to make them permanently more theatrical. Subtly illuminated with flickering “candlelight” and hidden fiber-optic lighting on gilding, these rooms are transformed by a subdued glow under darker ceilings. New taffeta draperies and tassels have been fabricated with luxurious simplicity that blends rather than upstages the true treasures on view. As I walked through the rooms with a friend, we were entranced by the artificial “daylight” that emanated through French doors: in one, a brilliant gleam of sunrise, and in another the pale luminosity of what my friend called “an afternoon in Paris when the sun never quite shows.”

Who knows what the future holds for the Met in decades to come? Thanks to the curators, architects, designers, and workmen in our time, I am enthralled.