Family ties are common in the Harbor City Music Company - eight women are mothers and daughters, and there are at least two sisters - and one of the daughters says it helps them harmonize.

The camaraderie also may have helped the barbershop chorus, which rehearses at the Chesapeake Arts Center, excel at last month's Sweet Adeline International Convention in Nashville, Tenn. The 58 members won the Harmony Achievement Award and then sang with nearly 7,000 other barbershop singers as part of the world's largest singing lesson, certified by the Guinness Book of World Records.

"It was actually pretty cool to think...