Swann was associated with the music ministry of the famed Riverside Church in New York City from 1952 through 1982, first as a substitute organist for Virgil Fox and then appointed Organist in 1957, when Fox's appearances at Riverside became infrequent until his departure in 1965 to pursue a full-time career as a concert performer. Upon the retirement of Richard Weagly as Choir Director in 1966, Swann became Director of Music and Organist through 1982.
Swann was affiliated with the music department at Riverside Church in New York City from 1952 to 1982, initially serving as a temporary organist for Virgil Fox and later becoming the permanent Organist in 1957. When Fox's performances became less regular after 1965, Swann took on a full-time role as a concert musician. In 1966, he succeeded Richard Weagly as Choir Director and remained in that position until 1982.