More than half a million people are expected to crowd along the Charles River in anticipation of the 39th annual Boston Pops Fireworks Spectacular at the Hatch Shell Wednesday night.

Keith Lockhart will lead the Boston Pop's Esplanade Orchestra for the 18th time, joined by featured performer Jennifer Hudson, host Michael Chiklis, and others. But, before that, WBUR's Steve Brown went down to the Esplanade to catch up with Lockhart and talk about what this event has come to mean to him.