William Hayman Cummings was an English musician, tenor and organist at Waltham Abbey.
He was educated at St Paul's Cathedral Choir School and the City of London School, becoming a pupil of Dr E.J. Hopkins, J.W Hobbs and Alberto Randegger, and was for many years a chorister in St Paul's Cathedral and the Temple Church.
In 1847, as a teenager, he was one of the choristers when Felix Mendelssohnconducted the first London performance of his Elijah at Exeter Hall. Cummings also sang at numerous festivals and concerts throughout Great Britain and twice toured in the United States. He is credited in 1855 with linking Mendelssohn's tune to Charles Wesley's words Hark! The Herald Angels Sing, which are now universally inextricably linked. At the Birmingham Festival he was the last-minute tenor soloist at the premiere of The Masque at Kenilworth (1866) by Arthur Sullivan, taking Mario's place (with only half-an-hour's notice to prepare).
Cummings founded the Purcell Society in 1876. He served as singing professor at the Royal Academy of Music for 15 years beginning in 1879, then became a professor and later the principal of the Guildhall School of Music. One of his notable pupils at the school was conductor Bruce Carey. He received an honorary Doctorate in Music from Dublin University in 1900 and was made a gentleman of the Chapel Royal. In 1902, he published a book on the origins of God Save the King.