A special event is being held tonight in Manhattan to commemorate the 50th anniversary of Dr. Martin Luther King Jr.'s final speech.

An audio recording of King's "I've been to the mountaintop" speech will be played Tuesday night during a ceremony at Washington Square Park.

The speech was delivered on April 3, 1968, one day before King’s assassination in Memphis, Tennessee.

Mayor Bill de Blasio and first lady Chirlane McCray will be on hand to light the Washington Square Park arch before the recording is played.

The ceremony is set to begin at 7 p.m.