It is rare indeed that the location of a new building should be as spectacularly correct, and as manifold in its promise, as the one proposed last week for the Museum for African Art. If all goes to plan, this institution will have its first permanent residence at the corner of Fifth Avenue and 110th Street in time to celebrate its 25th anniversary in 2009.

The charm and the majestic aptness of this choice are twofold. For one thing, it represents the extension of Museum Mile by six blocks beyond what, at present, is its northernmost point, the Museo del Barrio at 104th Street. If the Frick is taken as the southernmost point of Museum Mile, the promenade will now be officially two miles long.

Second, there is a tremendous metaphorical power to the museum’s occupying 110th Street, where, you could argue, Harlem begins. In one go, this institution will be the northernmost Museum on Fifth Avenue and the southernmost institution in Harlem. In one go, it will extend a New Yorker’s cultural options, all the while underscoring that Harlem, with its energetic development, is no longer off-limits to the downtown crowd. For the first time, Harlem will form part of a seamless continuum. What a vast responsibility to serve as the nodal point for the two halves of Manhattan! But the Museum for African Art seems up to the challenge.

The vast improvements to Harlem that have taken place thus far will doubtless be accelerated and enhanced by the arrival of the museum on a street that has already seen a remarkable transformation in recent years: From both the sumptuously laid out Duke Ellington Circle, which sits kittycorner to the museum’s future site, and 111 Central Park North, a residential high-rise on Lenox Avenue (or Sixth Avenue in downtown parlance), to the ongoing work at the intersection of 110th and Central Park West, a plaza that, we must hope, will turn out as successfully as Duke Ellington Circle on Fifth Avnue.

The museum’s footprint will be Lshaped and face north, dividing neatly in two, its southern half topped by a 20-story residential tower. Both halves of the museum itself will contain 90,000 square feet, of which 16,000 will be devoted to the exhibitions temporary and permanent. The rest of the museum will contain offices, a shop, an “event space,” and a theater than can seat several hundred visitors. There will also be a capacious roof garden that faces north and is contained in a wall, five stories high.

The only problem with the project is the design of the building itself, and that, of course, is a big problem. The main issue with the design is its attempt at contextualism, an architectural strategy for which the project’s architect, Robert A.M. Stern, is famous. In seeking contextualism in the present circumstances, however, Mr. Stern has sought to do what is probably impossible. The various typologies of African architecture tend to apply to far smaller structures than what is being attempted here. That in itself is not insurmountable, but it does seem counterintuitive, at the least, to try to marry an element of African vernacular to the modularity of modernism, which is to be deployed through the structure. This one motif consists of a wall whose window-spandrels tilt inward, creating a wobbly movement that is supposed to suggest lumber pillars of traditional African architecture. But even if that association will make sense to New Yorkers, its visual impact is underwhelming in an architectural context where real power is wanted. This is especially true given that the conceptual heart of the design is a modernist grid that does not take kindly to such subversions and that, by its very nature, denies the possibility of the sort of drama we should want and expect here. Furthermore, this observance of the African tradition conflicts with the context of Upper Fifth Avenue. What is wanted, then, is not a attempted compromise or rapprochement between modernism and African tradition but a more emphatic form of one or the other, or an altogether third thing that will be simply dazzling — context be damned.

As it is, there is a workmanly efficiency to the design’s exterior, which — aside from that single African motif — behaves much like any other modernist residential building in New York and thus is functionally divorced from the museum. Were it not for the African roots at the base of the structure, you can be sure that Mr. Stern would take this occasion to create a truly contextual building, like the one that he has designed for 15 Central Park West.

The interior of the museum appears to have a bit more of the requisite drama, with a lofty hall and lobby facing north, with its facetted and earth-toned interior wall curving inward. There is also to be a grand stairway inspired, we are told, by Louis Kahn’s famous stair case at the Yale Art Gallery. It is too early to gauge the success of these interior elements, but the exterior would profit from some fundamental rethinking. Surely, it is not bad in its present configuration, but it could be far better.

jgardner@nysun.com