King Hall also wrote two primers for Estey Organ, the American maker of reed organs and harmoniums. Both were published in 1880. He included in the organ primer his own testimonial for the instrument, saying "The tone of the Stops individually is mellow and sweet, and entirely free from the harshness which so frequently characterizes Reed Instruments; while the ensemble stresses solidity and fulness, and resembles very closely that of a thoroughly good Pipe Organ." That same year, King Hall wrote a short piece for a popular girls' magazine about the challenge of playing the harmonium, urging frustrated novices to persevere and "not let your disappointment keep you from trying again." King Hall was one of the few English composers writing specifically for the harmonium at the time.