“Red de Naranja” by Juls Gabs is part of the Cambridge Art Association show “Aura.”

The Cambridge Art Association show “Aura” opened Wednesday. Juried by Tessa Bachi Haas, an assistant curator at the Institute of Contemporary Art in Boston, the show is, put simply, a vibe.

The “aura” theme is vague but expansive. It’s an invitation for artists to experiment, to question their approach and to let the materials take center stage. In her juror’s statement, Haas acknowledges that in her career, “I have not often thought explicitly about an artwork’s vibes.”

Thank god she did. The selected works in “Aura” are playful and unexpected. Photographs by Somerville’s Gary Duehr zero in on close-ups of trash, enclosing each tightly in a circular frame – a visual nod to aureoles, the circles that represent angels’ halos in old religious paintings. “Red de Naranja” by Cambridge’s Juls Gabs is a clever twist on a still life. A hand grasps a red net that holds an iPad with a digital painting of fruit. Kay Hartung’s “Geocolor 19” brings encaustic (hot wax) paintings to life on wood in vivid blocks of color. The artists are clearly using materials to give form to their ideas.

“Aura” is a reminder that the best exhibitions aren’t always didactic, but can also be mysterious. They are allowed to be amorphous, open-ended for the artists involved – and unlocking things in the viewer rather than closing them off.

“Aura” is on view through Jan 17 at the Cambridge Art Association, 25 Lowell St., West Cambridge, and CAA@ University Place, 124 Mount Auburn St., Harvard Square, Cambridge.

Share your own 150-word appreciation for a piece of visual art or art happening with photo to [email protected] with the subject line “Behold.”