Alan Jackson gave a very special performance of his classic song, "Where Were You (When the World Stopped Turning)," at the 2015 ACM Awards.

Troy Aikman was on hand to introduce Jackson, saying, "Today, April 19, 2015, is the 20th anniversary of the bombing in Oklahoma City that killed 168 people. It affected everyone across the nation, but its impact was especially deep and tragic for those of us from Oklahoma. None of us will ever forget where we were when we heard the news of that attack, nor will we ever forget how our friends and neighbors rallied to help their brothers and sisters."

Aikman's sister was one of the first responders that day.

"Although this next song was written about a later horrific event, the World Trade Center attack on September 11, it resonates with all of us who grieve over what happened 20 years ago in my home state," Aikman added.

Jackson gave a somber, subdued performance of the song that underscored its emotional lyrical themes.  It's one of a number of very special awards show moments that he's created over the course of his career. It demonstrated his ability to deliver a simple song with heartfelt passion, which is the cornerstone on which he's built his legendary career.

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