In 1963, some singers in the Philadelphia suburbs expressed an interest in starting a chorus that would dedicate itself to both musical excellence and community service.
After choosing the suburb of Bryn Mawr as their initial location, the men incorporated as a chapter of the Barbershop Harmony Society.
The Bryn Mawr Mainliners chapter competes in the Atlantic Division of the Mid-Atlantic District of the Barbershop Harmony Society.
After their first victory in 1991, the Mainliners again won the District Championship in 1991 and attended the International contest in 1992 in New Orleans under the direction of Bill Oppenheim placing 19th.
The Mainliners again represented the Mid-Atlantic District on the International stage in 1997 in Indianapolis and placed 16th under the direction of Rick Serpico.