One of my favorite vintage jazz songs is “All the Things You Are,” Jerome Kern’s 1939 composition with Oscar Hammerstein’s lyrics. It floats down the keyboard: B-flat, E-flat, A-flat, G7 — challenging for a piano player. It was on my mind last week while I was exploring our region with our two grandkids, 4-year-old Lou and 2-year-old Mosey, and their parents.

The first afternoon, we climbed all over Cromwell’s Kaleb Anderson playground, four adults trying to keep up with the ecstatic Lou and coaxing Mosey to try the steeper slides. Once school got out, a gaggle of kids arrived...