No matter how frivolous it is from a functional point of view, ornament has a symbolic power that makes it seductive, endearing and meaningful.

We still enrich our presence with ornaments of one kind or another and seldom worry about how rational it is.

Sometimes, the more irrational, the sexier. A curious exhibition called Sweet Spot at the Ian Potter Museum of Art investigates this conundrum. Perhaps taking its name from the elasticity of a tennis ball striking the centre of the strings, Sweet Spot suggests the zing of a special zone that we choose to adorn. For example, the sweet spot could be erogenous. Kevin Maritz seems in no doubt.

His sculptures resemble giant pearl necklaces laced over abstracted genitalia. As the curator's notes confess, "the sculptures have erotic overtones".

In a more explicit example, the necklace dangles from the centre of two steel breasts, attaching itself to the figurative nipples.

The intimate space of a neck is confounded with the massive proportions of the museum. It's confronting that Martitz enlarges it to the point that the necklace is like monumental wall sculpture or painting. By manipulating scale in this way, Martitz suggests that all art is a form of erotic sublimation.

Another work resembling a necklace is a cool circle of luminous pearls by the late Neil Roberts. Actually, the pearls are table tennis balls, drilled and threaded over a thin neon tube. Lit from inside, the translucent balls radiate sumptuously, a diaphonous sweet spot quite beyond their normal bounce.

As if an allegory of all things vain and human, however, the circle of table tennis balls is not entirely perfect. The positive and negative ends of the tube can never connect, else there would be a short circuit. So the circle does not complete itself and the ideal aesthetic sweet spot has a leak.

Roberts also used leadlight decoration to express the thumping action of boxers, a work that might not have immediate punch but implicates the tradition of ornament in rupture and ritual violence.

Up to a point, these are themes pursued by Tony Clark and Adrienne Gaha, both of whom draw upon the mighty ornamental traditions of painting.

One of Clark's pictures shows a horse from Phaethon's chariot tumbling from the sky. In two others, the decorative babies used in art (known as putti) look distraught.

Clark's paintings have a rough quality that contrasts greatly with the premodern sources. Adrienne Gaha remains closer to the drawing of the great periods of decorative painting but still shows figures tumbling in contest with text and contemporary imagery.

Peter Kennedy rehabilitates the gumtree, that stalwart of suburban lounge rooms and ornamental golden frames, but he makes it spring to life in dark and lurid graphic contortions. You don't really feel that the eucalypts are noble woody friends under which you might seek refreshment from the sun so much as a strangulatory nest surrounded by trouble and gloom.

Elizabeth Pulie is perkier with her graphic swirls and fill, evoking ornamental traditions more than Marie Hagerty's ambiguous organic imagery. Some of Pulie's pictures have the witty title Signature, which links them with the illegible loops of pen produced in signing a cheque.

So what is a sweet spot? A resonance amid contradictions? You come out hoping that this is what the curator Joanna Bosse intended by this obscure but evocative show.