Organist Richard Miller pages through a thick volume in the choir loft at the Moravian Old Chapel in Bethlehem’s Historic District.

“I don’t want to run out of music,” he explains.

There is little chance of that. The organists’ reference consists of about 848 hymns, some dating from the mid-1750s.

Music is essential to Moravian identity.

Bethlehem’s underwriting founder, Count Nicholas Von Zinzendorf, used to write hymns by campfire while on missionary missions. From hundreds of miles away, he would dispatch messengers home with copies of his hymns. Included also were exacting performance schedules, to synchronize simultaneous singspiel (its term for the faith’s hymn singing) on the trail and at Bethlehem.

“He was,” Miller says, “an over-organizer.”

The organists’ reference credits the Count with 24 hymns.

Over 30 years, Miller has not run out of music while serving as pianist, self-taught choir master and, with installation of an organ in 2014, self-taught again as organist.

At the age of five, he started piano lessons with Clarence Willitts of Fullerton. Then came sight-reading lessons with Allentown’s Jean Fox, later his mentor. He played the trombone and joined the Asbury Methodist Church children’s choir.

His Old Chapel choir, now with 14 members, “organized itself,” he said, with him as director.

Parishioner Helen Seifert remembers that Miller’s mother used to watch over him as he played in the Chapel.

“He is,” she pauses, hunts for words, then adds, “an inspiration.”

Rev. Janel Rice, the Bethlehem congregation’s pastor, credits Miller with an “extreme dedication in passing along the craft and spirit of our faith’s mission.”

A few words about the Old Chapel: Its thick stone walls date from 1751, about a decade after the congregation moved from Philadelphia to Bethlehem. It adjoins interconnected buildings in an area newly designated as a World Heritage Site.

Worshippers there, during the Revolutionary War period, included George and Martha Washington, John Adams, Samuel Adams, Benjamin Franklin and the Marquis de Lafayette. In 1792, leaders from the Iroquois Federation met there to pray for continuing peace.

On a whimsical note, Miller in 2014 authored an illustrated children’s book, centering on a quest around Bethlehem’s Historic District to locate baby ducklings. “Fred Snuffelnose and the Baby Ducks,” is available from publisher Milton & Hugo or from booksellers on line.

The cover depicts ducks outside the larger Main Sanctuary, where May 25 a celebration was planned to mark Miller’s 30 years. A reception followed.