COGIC became a staple of gospel music under the guidance and leadership of Dr. Mattie Moss Clark. (1972–1994). She revolutionized and reorganized the music ministry to become a leading department in the church. She developed the role of the State Minister of Music and traveled the world conducting seminars and workshops perfecting the quality of choir music, their performance, appearance and demeanor, and the COGIC sound. Under her leadership and tenure, COGIC choirs and individual singers came to dominate gospel music producing a number of recordings and gospel hits. She formed her daughters into a singing group who became known as the legendary "Clark Sisters" who helped introduce and became leaders of the contemporary gospel music era. In 1982 during the Seventy-Fifth Holy Convocation, the diamond jubilee of the church, COGIC published its own hymnal, "Yes, Lord!", which included many arrangements and songs written by COGIC and African-American musicians and songwriters. She is the longest serving president of the International Music Department and her influence and legacy have been indelible and are recognized around the world.