Stepping Up with Thornton Willis

A senior figure in American abstraction, Thornton Willis is nearing his 75th birthday and painting at a high a level as ever. Working forward from a 2009 exhibition which saw him using a post-and-lintel formation to build his pictures, he has moved on to stacking blocky shapes that similarly recall architecture while allowing him to employ a vibrant palette. "In the Grid" opened yesterday, and runs through April 23 at Elizabeth Harris Gallery, 529 West 20th Street, 6th Floor, between 10th and 11th avenues, 212-463-9666, eharrisgallery.com.