Watch: President Obama sings "Amazing Grace" at funeral for Rev. Pinckney, in Charleston

Delivering a eulogy at the funeral for Reverend Clementa Pinckney, killed in the Charleston church massacre with 8 more by white supremacist Dylan Roof, President Obama sings "Amazing Grace."

The hymn holds a special place in Black American History, and was written by a former British slave trader.

Amazing grace! (how sweet the sound)
That sav'd a wretch like me!
I once was lost, but now am found,
Was blind, but now I see.