Roni Horn: Dia Center for the Arts. (New York).

When an artist settles into the niche of her obsessions, the line can become very fine between the rote re-presentation of a signature discovery and the passionate revision of a central but enigmatic urge. Twenty-some years into her career, Roni Horn's field of interest is well-defined, notwithstanding the fact that her subjects-- indeterminacy, doubleness, and motion-- are inherently difficult to pin down. Her current show, the first of a two part installation spanning eight months, is based entirely on strategies she has deployed before; in a way, there was nothing new to see. So why did the galleries feel so charged?

The answer has to do with the fascination of fluctuation and multiplication, and also with the self-renewing pleasure of focused formal inquiry. Horn makes masterful use of a combinative effect that poises the rhythmic predictability of seriality against minute tonal shifts; her installations feel both massive and atomized, forbiddingly solid and disconcertingly palpitant. She grapples with the maddening and/or ecstatic drift that plagues representational systems, the tenuous connection between extant objects and their names or pictures, which Roland Barthes called "the floating chain of signifieds." According to Barthes, the need to make meaning tidy, to fix this unreliable chain reaction and thereby ward off "the terror of uncertain signs," gives rise to all language, all ideological schemes of interpretation. The logic of Horn's work assumes that the serialized frieze or grid of photographs, as well as the floor-based serial sculpture, is a system of meaning whose very blockiness and regularity seeks to q uell or contain the wild polysemy of its referents (objects, faces, atmospheres).

The lengthy exhibition title quotes a ditty by George and Ira Gershwin in which love-song cliches make end rhymes (hair/care, eyes/skies, moon/croon, above/love) preceded by "blab, blah, blah." Such attention to linguistic inflection, the play between sense and nonsense, is key to Horn's method, as the title of one of the three photographic series here suggests: In "Clowd and Cloun (Gray)," 2001--whose name contains a failed doubling perceptible only to the viewer who sees the title in writing-- blurry gray pictures of clouds alternate with indistinct portraits in which the red smears of clownish nose and lips can be discerned. This piece in turn rhymes with "This Is Me, This Is You," 1999-2000, a double grid of portraits of one highly emotive little girl. She grimaces, stares, yawns, neither pretty nor cute but articulate. Hung on opposite walls, the Me/You grids mirror each other, but not exactly, forcing the eyes to oscillate between them, trying to fix pairings that never quite match. Meanwhile, "Some Th ames," 2000, reiterates Horn's longtime attraction to water as an emblem of totality and change. In saturated teals, grays, ochers, and cobalts, the close-ups of agitated river surface--which, of course, are frozen in photo-eternity--inscribe a horizon line around the room.

For the second part of the show, "Clowd and Cloun (Gray)" will be replaced with "Clowd and Cloun (Blue)," and "Some Thames" with a new photographic series, "Becoming a Landscape." The girl with the elastic features will stay, as will the final piece in the installation, a two-part cast-glass floor sculpture called "Untitled (Yes)," 2001. This comprises a huge block of transparent glass in one room and in another a matching, highly polished glass block in black. Clarity and opacity, ice and oil, sky and earth, thought and ink offer themselves as possible referents, potential captions with which to stabilize the conscious stream on which these chunks of substance float. What is the correct answer, the single, fixed significance? Yes.