Born in London, Cusins studied music in Brussels under François Joseph Fétis and later at the Royal Academy of Music in London. He was appointed Master of the Queen's Musick in 1870, and was knighted in 1892.
He toured widely in Europe as a pianist, and produced editions of the piano music of Robert Schumann. Among his works as a composer are the oratorio Gideon, an overture to William Shakespeare's Love's Labour's Lost and a piano concerto.