Art exhibitions with a gimmick run the risk of being too... well, gimmicky
. Which is why "Birdspace: A Post-Audubon Artists' Aviary," last summer at the Norton, was especially amazing. For one thing, it was a large show that included more than 70 works by 50 artists. For another, it paid homage to an artist of great historical importance, the peerless John James Audubon. The art was limited to works connected in some way to our fine feathered friends, but beyond that, anything was fair game. And while most of the artists were Americans born in the mid-20th Century, their art was all over the map. A few stuck to fairly traditional media; others pushed boundaries and political hot buttons. Despite all these things, or maybe even because of them, it was an enormously satisfying exhibition in which an array of often fascinating parts added up to an even greater whole.