IN 1935, the summer after my first year in college, my friends Tom and Dave and I drove from Pennsylvania to Niagara Falls and then on to Canada. In Montreal we attended a movie theater where Duke Ellington’s orchestra was featured onstage.

Following the performance, Dave decided to pose as a reporter for his college newspaper, with the hope that the three of us could get backstage to meet the Duke. We went to the stage door, the bandleader agreed to be interviewed, and we were escorted to his dressing room.

Pencil and pad in hand, Dave asked Ellington to define swing. The great man answered, “That part of rhythm that causes a bouncing buoyant terpsichorean urge.” We departed with autographed pictures for each of us.

Within a year, Tom died in an automobile accident. Dave was killed in action in Europe during World War II. The photograph is a treasured memory.