One of the most well known hymns.

Title: Fantasia on Come, Thou Fount
Composer: John Purifoy
Tune: Nettleton (from the original song) Wyeth's Repository of Sacred Music (1813)

There is history with this hymn that is covered in a magazine called The Church Pianist, "The Pianist's Companion for the Church Year - Larry F. Pugh, Editor", dated July/August 2012. Concerning "Fantasia on Come, Thou Fount" Larry wrote:

With his father dead and his mother unable to discipline him, Robert Robinson's mother sent him to London to learn barbering, where he also learned "the ways of the world." One night, following a disturbing incident with a fortuneteller, Robert went to hear evangelist, George Whitefield, an experience that changed the direction of his life. The transformation took a while, but by the time he was 20 years old he was on his way to becoming a minister. On Pentecost Sunday three years later, the now Rev. Robinson wrote this hymn to go with that day's sermon. The composer of the Nettleton tune is not known, but we do know it was named for another well-known evangelist at the time, Ahasel Nettleton. John Purifoy enhances his stirring arrangement with a succession of fanfares and, as he instructs the pianist, "with great energy."

Lyrics:
Come, Thou Fount of every blessing,
Tune my heart to sing Thy grace;
Streams of mercy, never-ceasing,
Call for songs of loudest praise.
Teach me some melodious sonnet,
Sung by flaming tongues above;
Praise the mount—I’m fixed upon it—
Mount of Thy redeeming love.

Here I raise my Ebenezer;
Hither by Thy help I’m come;
And I hope, by Thy good pleasure,
Safely to arrive at home.
Jesus sought me when a stranger,
Wand’ring from the fold of God;
He, to rescue me from danger,
Interposed His precious blood.

O to grace how great a debtor
Daily I’m constrained to be!
Let that grace now, like a fetter,
Bind my wand’ring heart to Thee:
Prone to wander, Lord, I feel it,
Prone to leave the God I love;
Here’s my heart, O take and seal it;
Seal it for Thy courts above.