Raymond and Elizabeth Chenault, a husband-and-wife team known as “America’s Most Famous Organ Duo,” performed organ duet instrumental selections Sunday as part of the First Presbyterian Church of Gainesville’s 2013-14 concert series. The couple has played at some of the largest venues in America and Europe, including Washington National Cathederal, St. Paul’s of London and the Spoleto Festival. Michael Henry, director of music at First Presbyterian, knows the Chenaults from working together at All Saints Episcopal Church in Atlanta.