As we leave LaSalle Street to catch a bus for an afternoon at the Shedd, the sound of a busker’s Deerness Two Step coming up the corridor of red marble attracts our daughter, pulling her forward in the stroller. We round the corner before the escalators and she begins to laugh at the carefully suited, smiling man with tufts of white hair blooming like open cotton bolls under his fedora. Reflected light makes the steel strings of his fiddle shimmer, shine like Orion’s Belt where they cross the flattened arch of the bridge behind the bow. My wife lifts our toddler, stands her on the stack-bond tile where she strikes that spread-legged, arm-flapping stance universal to happy two-year olds and begins to dance. Meeting her energy, accustomed to audiences of all ages, the maybe-a-grandfather shifts to The Blue Danube Waltz, rises fluidly, and twirls around the space with a maybe-future-Terpsichore keeping place by his side until the music ends. They bow, resume respective seats, and wave each other good-bye, off on their memory-joined journeys.