“Hello. I’m Grandpa.”

For Christmas 50 years ago, my parents splurged and bought me a compact reel-to-reel tape recorder. My father had whetted my appetite with remarks that one could build a primitive voice recorder along the lines of Thomas Edison’s prototype, but this was the real store-bought deal.

I took the prized possession along when my paternal grandparents hosted Christmas dinner for the very last time.

I THINK the device is still nestled in my mother’s attic; but even without it, I distinctly remember Grandaddy Carl neglecting his King Leo stick candy long enough to lean forward and...