Faced once again with a deeply challenging and painful tragedy, in June 2015 President Barack Obama was called to deliver a eulogy for the Reverend Clementa Pinckney, one of nine people murdered at the historic Emanuel AME Church in Charleston, S.C., by a hate-filled gunman.

As he had done so many times before, as our best presidents -- FDR, Kennedy, Lincoln -- have done in crisis and challenge, Obama spoke to the soul, courage and love of our nation. When people could have felt demoralized, he “re-moralized” our nation, fixed our compass to true north and reminded us of who we are and who we aspire to be.

Then, the unexpected: Just when his speech had seemed to reach its moving conclusion, the president began to sing. As he hit the notes of “Amazing Grace” in an unchanging baritone, his voice steady and resolute, he lifted us all a little bit higher than we thought we could go. Obama’s leadership has exemplified what America can be at its best, even when we are confronting ourselves at our worst. He has led our country with grace and scandal free dignity for the past eight years.

His presidency has been rife with challenges -- he inherited a nation on the verge of financial meltdown, engaged in two wars and with a deeply rooted, unyielding partisanship that has only become fiercer. In spite of those challenges and others, Obama has ably led our nation to greater prosperity, and, despite the rise in global threats, has not allowed us to surrender our values of freedom and compassion and our commitment to being strong amid a storm.

History will herald Obama’s many accomplishments: bringing America back from the brink of financial collapse, negotiating the groundbreaking Paris Climate Agreement, cutting the unemployment rate in half, starting to fix our broken criminal justice system, expanding health care access for millions and many more. But I believe he and his family also leave a legacy of helping us as a nation to see each other more clearly, to recognize the breadth and the depth of the beauty, promise and potential of a diverse America.

This black family in the White House expanded the moral imagination of us all and helped a generation of children from all backgrounds to dream bigger and more inclusive dreams for themselves and their country. Shortly after Obama was first elected, I visited a majority-black classroom across the street from where I lived in a low-income section of Newark, N.J. I asked a familiar question to the elementary-aged children: “What do you want to be when you grow up?” I expected to hear a familiar answer, which was usually the name of whatever celebrity had captured their imagination at the time, most often an entertainer, artist or athlete.

But this time, the answer was different from anything I had heard before: More than one child proudly and confidently proclaimed, “I want to be president of the United States.”

As Obama leaves office, I will remember him as a man who not only gave kids on my block a bolder hope for their own future, but as someone who in dark times helped to show us all that we are better than the sum of our parts, that we are the United States of America, and together -- if we can recognize that the ties that bind us are stronger than the lines that divide us -- we can achieve impossible things.

By the second line of “Amazing Grace,” everyone at Reverend Pinckney’s memorial service joined the president in song. As those behind Obama and in the crowd began to sing, their voices grew louder, and the president’s own voice became less discernible. He had ignited the strength of the chorus -- a choir of healing and hope -- and the strength of that collective of voices was all anyone could hear.

This article originally appeared in the Jan. 14 issue of Billboard.