Sculpture that remains alive should have a dialogue between the spectator and the piece itself. If they are drawn to it by a question, I think that's really important. It's like poetry. You read something of Emily Dickinson and you scratch your head. At 20, it means one thing. At 30, another, at 40, another, and at 60, it continues to live.

New Hampshire sculptor Ernesto Montenegro talks about his art eloquently and, at the same time, does a good job of describing his own work.

"Shadows in Bronze," a show of Montenegro's sculptures, from diminutive reliefs to monumental bronzes, is on view at the R. Michelson Galleries in Northampton through the end of the month and it's well worth taking a break from the holiday madness to make a trip to see his work, on display in two second-floor exhibition rooms.

Montenegro's pieces reach out and grab you, with music or silence, humor or drama, pell-mell movement or breathless stillness. His work includes free-standing sculptures and reliefs, all fashioned from bronze, a medium which he exploits to the fullest.

A series of reliefs depicting musical performers illustrate Montenegro's skillful synthesis of both negative and positive space, of two and three dimensions, and of light and shadow. "Jazz pianist," for example, shows a man sitting at the piano, his hands poised above the keyboard as if caught in midbeat between blues rifts. The figure's arms emerge from the surface of the relief as three-dimensional sculpture, casting a shadow onto the piano keyboard, which also juts out from the vertical plane of the bronze panel. The head also stands free of the surface behind it, but it is looks like a two-dimensional cutout, as if Montenegro has taken to the metal with a pair of scissors. In contrast, the legs are inscribed in the surface like a drawing, with a looseness that suggests the artist is working with clay instead of metal.

The interplay of light and dark created by the juxtaposition of two-dimensional and three-dimensional shapes creates the illusion of movement - as if the figure's head has just emerged from the shadows into the light or his foot has shifted under the piano. The artist's playful and varied manipulation of the medium gives his sculpture a richness and an ambiguity that yields one surprise after another as you ponder his work.

Montenegro began his career in 1969 when he responded to a suggestion from famed sculptor Henry Moore - that he needed more experience before becoming an apprentice - by heading to New York City to immerse himself in art. There, he worked as a shoe salesman in the morning and spent his afternoons drawing at the Metropolitan Museum of Art.

He went on to study in France with sculptor John Skeaping, a friend of Moore's, later apprenticing with a stone sculptor in the States. One of his first major works, a bronze titled "Via Crucis," which depicts the 14 stations of the cross, won the Religious Sculpture Award of Monte Carlo's Gran Prix d'Art Contemporan. After moving with his family to New Hampshire in 1990, Montenegro continued to win awards for his work, which was exhibited widely, including at Federal Reserve Gallery and the Fogg Museum, both in Boston.

Montenegro's work spans a variety of styles and influences, incorporating both abstract and realistic elements. His small free-standing bronze sculpture "Rush Hour Chimera" recalls the whimsical surrealism of Salvador Dali. The piece suggests the crush of a busy sidewalk with a collage of sculpted heads, joined in a horizontal jumble atop of a pair of legs leaning forward at a perilous diagonal. Leading the pack is the hatted head of a man that is dissected vertically in half as if he his figure is already disappearing inside a doorway.

Mounted on the wall, the large sculpture "Crosswalk" gives the viewer a bird's-eye perspective, as if looking down from above on pedestrians walking across the street, an illusion Montenegro achieves - magically - by dramatically foreshortening the figures. Seen from the side, the people have grossly stunted legs and, walking down the vertical face of the wall towards the floor, seem propelled across the street by the pull of gravity.

There are many other striking works - "Anne Frank," "Tribute to 9/11" and "Pompeii Couple," to name a few - that make this exhibition one of the finest at Michelson's this year.

"Shadows in Bronze" runs through Dec. 31 at the gallery, 132 Main St., Northampton. Hours are: Mondays through Wednesdays, 10 a.m. to 6 p.m.; Thursdays through Saturdays, 10 a.m. to 9 p.m.; and Sunday, noon to 5 p.m. For information, call 586-3964 or visit www.RMichelson.com.