The corks are popped, the wine glasses polished. Brushes are lined up in neat rows. Canvases are poised in waiting. Pop on Sinatra, and all is ready to go.

It’s Saturday night in Clarinda, and the next session of wining and painting is about to begin at Painting Barn Studio, the area’s contribution to the latest artistic social gathering craze.

“It’s just a great time of music and wine, and some painting,” says...