The Octorara Covenanter Presbyterian Foundation is turning to a pair of familiar faces for its celebration of America's 250th birthday.

Charlie Zahm and Tad Marks will join together to perform "The Liberty Tree: The Music That Forged a Nation" on Sunday, July 12, at 6 p.m. at Middle Octorara Presbyterian Church, 1199 Valley Road, Quarryville.

Zahm and Marks have long been mainstays of the Covenanter Scottish Festival and Highland Games, performing at every iteration of the festival, expect for 2014, when they were out of the country.

"He is just such a wonderful storyteller," event co-chair John Girvin said of Zahm. "He has a background in history and degree in history, so he researches everything that he does."

The event will celebrate 250 years of American freedom with songs and stories of the days gone by, organizers said. There will be a price for general admission; children 12 and under will get in free. Attendees have the option of adding a donation to the Octorara Covenanter Presbyterian Foundation.

Girvin said that the event was intentionally scheduled as close to the Fourth of July as possible.

"We feel like this program honors the United States, celebrating their 250th, but also highlights the birth of the country, which featured a lot of involvement of Scots-Irish folks," he said. "Many of those were living in Lancaster County Chester County and obviously played a very important role in the beginnings of our country."

Zahm serves as the group's vocalist; he also predominately plays the guitar. Marks completes the group's lineup as the fiddler. The Liberty Tree has a busy month with the anniversary, playing shows all over Pennsylvania, Delaware, Maryland and New Jersey.

Organizers said that attendees will have the opportunity to step back into the stirring soundscape of early America with an unforgettable concert celebrating the songs of liberty that inspired a young nation. Girvin suggested "Yankee Doodle," "Chester" and "The Liberty Song" as tunes that will reverberate at the church on the night of the event.

"Whatever presentation (Zahm has) done, his garb is just amazing," Girvin said. "I just can't say enough about the fact that he is all over the East Coast, too. If you see his schedule, he goes up and down the coast at different Celtic events and festivals."

Marks formerly played with the Del McCoury Band, a Grammy-winning bluegrass band. Zahm also performs as a solo act; he will undergo a tour to Wales next spring.

Ahead of the show, from 5 to 5:45 p.m., the historic church will be open to tour. The church is the oldest Covenanter church in North America, dating back to 1754. The schoolroom, a Presbyterian Academy, was added to the facility in 1871 and housed Bart Township High School from 1903 to 1927.

Middle Octorara Presbyterian will celebrate its 300th anniversary next year. Refreshments will be served following the concert; there is also an ice cream social in the works.

Tickets can be purchased online. To do so, visit the "Octorara Covenanter Presbyterian Foundation" on Facebook.

The Octorara Covenanter Presbyterian Foundation is a charitable and educational nonprofit organization that maintains the Octorara Covenanter Presbyterian Church and its attached schoolroom as a historical site. The museum displays artifacts from the Covenanter Congregation, the Middle Octorara Congregation, Bart High School and Bart Township. The desks from the Bart High School era are carved with vintage emblems.