Bruce Clark, who is pastor of worship and music at Christian Family Chapel in Jacksonville, explained they were singing with the piano because the church's pump organ is dismantled for repairs. The piano was rarely used in 18th-century churches, he said. "Catgut" churches allowed the cello and bass.
"Hymn tunes were named for places and people," he said.
Some hymns such as the Doxology had as many as 14 verses that told a story, so all the verses usually were sung.
A junior in high school, Micah has been playing the cello for nine years. He said Isaac Watts wrote essays as well as hymns, and the essays often were included in hymnals of the time.
The early Christians used the same Psalter that the Jewish people used, Susan Clark said.
"They sang that through the 16th century and only certain intervals - the distance between two musical notes - were allowed in church music." The augmented fourth was banned as "Satan's interval," she said, demonstrating it on the piano.
She added that "a vast library" of hymns from the 18th century exists because as people committed themselves to God, there was "an outburst of song."
Because some hymns were written by pastors to accompany their sermons, there were no copies for the congregation. The pastor lined the hymn - he sang a line and the congregation sang it back to him. Bruce Clark demonstrated the technique with "Grace 'Tis a Charming Sound."
"Watts didn't like his hymns sung that way," he added.
A student at Moody Bible Institute in Chicago, Hannah Clark told the group about Anne Steele, a hymn writer who lived from 1717 to 1778 and produced 160 hymns from a life of grief and suffering.
"She was 6 years old when her mother died, and as a teenager she fell from a horse and permanently injured her hip," Hannah Clark said. Two hours before her wedding, her fianc drowned. After that experience, she wrote, "Father, Whate'er of Earthly Bliss Thy Sovereign Will Denies."
Mary Ruth Reis of Silver Spring, Md., said after the service that the "setting was beautiful. This church comes alive" with music.
Cedric Duffield said his ancestors were among the settlers who founded the original congregation. All except his father are buried in the cemetery beside the church. Duffield and his wife, Julia, live within sight of the church.
The Clarks became interested in 18th-century church music after reading a magazine article and studying a hymnal from Wales, Susan Clark said.
"It's exciting to know there is still an audience for this," Micah Clark said. He added that presenting such programs with his family is "a lot of fun; not a normal activity by any means, but fun."