King Hall composed both sacred and secular music, especially sentimental ballads and organ voluntaries. He contributed regularly to the popular German Reed Entertainments at St. George's Hall, Langham Place. His obituary in "The Musical Times" called his German Reed music "his most popular works". Kurt Gänzl wrote that King Hall's music was "pretty forgettable." Yet, it gave steady, reliable satisfaction over the course of nearly twenty years with the Reeds. King Hall collaborated with such librettists as Arthur Law, F. C. Burnand, Gilbert Arthur à Beckett, Walter Frith and J. Comyns Carr, composing the scores for "Foster Brothers" (1877), "A Happy Bungalow" (1877), "Doubleday's Will" (1878), "A Tremendous Mystery" (1878), "The Artful Automaton" (1878), "Grimstone Grange" (1879), "A Christmas Stocking" (1879–1880), "A Merry Christmas" (1880–1881), "A Strange Host" (1882–1883), "The Naturalist" (1887), "The Verger" (1889–1890) and "Missing" (1894). Most of these entertainments were accompanied by piano and harmonium only.