Gaul was born in Norwich, where he studied under Zechariah Buck. By the age of nine he was a chorister at Norwich Cathedral, and at the age of seventeen he was appointed as the organist of the parish church at Fakenham. In 1859 he moved to Birmingham, where at the age of twenty two he was appointed organist at St. John's Church, Ladywood. In 1863 he took the Bachelor of Music degree at the University of Cambridge. He was Master of Music at St Augustine's Church, Edgbaston from 1868, the first Birmingham church to have a surpliced choir.
In 1877 Gaul started teaching the first classes in the theory of music, harmony and counterpoint at the Birmingham and Midland Institute, marking the first step towards providing a fully rounded musical instruction at the institution that would eventually become Birmingham Conservatoire. He would later be appointed as professor of orchestration and composition at the school. He taught singing and harmony at the King Edward VI High School for Girls.
Gaul wrote a large quantity of choral music in a simple melodious style influenced by Spohr and Mendelssohn. His cantatas were widely performed on the music festival circuit, with the best known The Holy City – premiered at the Birmingham Music Festival in 1882 – being the most popular of its era. At the time of Gaul's death in 1913 it was the most performed work of English choral music in history, and by 1914 over 162,000 copies of its full score had been sold. The Holy City and his earlier cantata Ruth (1881) were also popular in the United States.
Alfred married Alice Annie Motts and they had three daughters.
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- McGuire, Charles Edward; Plank, Steven E. (2011), "Gaul, Alfred R. (1837-1913)", Historical Dictionary of English Music: ca. 1400-1958, Lanham, Md: Scarecrow Press, p. 136, ISBN 0810879514, retrieved 2014-04-17
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