After graduation from the music course at Moody Bible Institute in 1915, W. (William) Plunkett Martin was elected as evangelistic singer for the Southern Baptist Home Mission Board. Following his marriage to Miss Ruby Stanley of Lafayette, Alabama in 1921, Martin accepted a call to become the Minister of Music at First Baptist Church, Shreveport, Louisiana. He later served at St. Charles Avenue Baptist Church, in New Orleans, the Evangelism Department of the Home Mission Board, First Baptist Church, LaGrange, Georgia, and Barton Heights Baptist Church, Richmond, Virginia. Martin received his Bachelor of Music degree from the University Conservatory, Chicago in 1944 and his Master of Sacred Music from Central Conservatory, Chicago in 1950. The honorary degree, Doctor of Sacred Music, was given by the same school in 1953.
W. Plunkett Martin became the first director, later known as dean, of the School of Music at New Orleans Baptist Theological Seminary, a capacity in which he served until his retirement in 1960. During his tenure, Martin guided the Music Department's growth into the E. O. Sellers Music Building on the new seventy-five acre campus at 3939 Gentilly Blvd. On July 28, 1959 the Board of trustees established the office of Dean of the School of Church Music. One of the significant contributions made by Martin is the Sellers-Martin Hymnal Collection. This collection contains over 400 hymnals, representing 239 titles, which once belonged to Ernest Orlando Sellers and William Plunkett Martin, who used them in evangelistic campaigns.