Singing in a show choir is something that runs in the family for sisters Nancy Disney and Jen Kuethe.

Their mother, Jane Hunt, was a longtime member of the Baltimore-based Harbor City Music Co. Mrs. Disney even met her husband, Scotty, at a choir function about 10 years ago.

"We're a very musical family," said Mrs. Kuethe of Glen Burnie, who remembers attending rehearsals with her mother when she was a child.

She and her sister, who lives in Odenton, are half of Harbor City's barbershop quartet Capri. Harbor City, which has about 70 members across Maryland and northern Virginia and 26 members from Anne Arundel County, is...