The Crusade for Christ took place in Washington, DC last year at the Washington Hilton where thousands of people gathered. Beautiful a cappella singing was an important part of the services that took place each night. Washington Post reporter Hamil Harris interviewed song leader Chris Turner and Daniel Harrison about the singing.
Take a listen.
A Cappella singing–singing without instruments.
King James Version (KJV)
19Speaking to yourselves in psalms and hymns and spiritual songs, singing and making melody in your heart to the Lord;