A painter (50 New Yorker covers) presents a series of square, full-page paintings, each captioned only by a lowercase letter. Even the close-up views and focus on elegant design rather than on literal representation of subjects like a staircase, a train track, or rowboats won't stymie most viewers, but—just in case—there's a key at the end. The paired paintings harmonize well; the sophisticated structure of the pairings even leads the eye from left to right. Like Hoban's photo books, unusual, provocative, and enriching. (Picture book. 5+)