Barnby was educated at the RAM and after serving as organist in several London and York churches he accepted a position as organist at St Andrew's in 1863. There he developed lavish choral services, including the first use of harp in an Anglican service (1866). He continued these services on an even grander scale at St. Anne's in Soho, where he founded a choir that served to introduce the public to then little-known works of Handel, Beethoven, and Gounod. Barnby was a prolific composer of mostly choral and vocal works. His compositions, influenced by Gounod, are melodic and emotional, and some remain popular to this day.