President Obama sings “Amazing Grace” during services honoring the life of the Rev. Clementa Pinckney, at the College of Charleston TD Arena in Charleston, S.C., June 26, 2015.

The song "Amazing Grace" was first performed on New Year's Day, 1773, and has gone through many changes over the years. SCOTT SIMON, HOST: You know those songs that you just kind of know?

In 1971, inspired by the commercial success of Judy Collins' single, the Royal Scots Dragoon Guards recorded a bagpipe version. (SOUNDBITE OF ROYAL SCOTS DRAGOON GUARDS' "AMAZING GRACE") BALABAN: ...

BALABAN: Jackson met Dr. Martin Luther King Jr. in 1956. She sang in Selma and at the March on Washington. And she even sang "Amazing Grace" to King over the phone at night to calm him down at the ...

In 1971, inspired by the commercial success of Judy Collins' single, the Royal Scots Dragoon Guards recorded a bagpipe version. (SOUNDBITE OF ROYAL SCOTS DRAGOON GUARDS' "AMAZING GRACE") BALABAN: ...

The song "Amazing Grace" was first performed on New Year's Day, 1773, and has gone through many changes over the years.

BALABAN: Jackson met Dr. Martin Luther King Jr. in 1956. She sang in Selma and at the March on Washington. And she even sang "Amazing Grace" to King over the phone at night to calm him down at the end ...

SCOTT SIMON, HOST: You know those songs that you just kind of know? You sing along without even thinking about the lyrics. Well, we're going to explore the history of one of these songs today. It's ...

And she even sang "Amazing Grace" to King over the phone at night to calm him down at the end of a long day. The song was becoming known as a balm for troubled times, and that was never more ...