John Challis (1907–74) was one of the first American harpsichord and clavichord makers. He studied the techniques of harpsichord making with Arnold Dolmetsch in England. When he returned to the United States in 1930, he established a workshop in Ypsilanti, Michigan. He later moved his shop to Detroit and then to New York City. One of his goals was to develop a harpsichord that would withstand the rigors of travel and temperature change. To accomplish this, he ultimately used aluminum rather than wood for the frame, as well as for other parts of the instrument. Ralph Kirkpatrick first contacted Challis in 1934 and commissioned a number of instruments from him in the 1940s. The letters between Challis and RK indicate both the pleasure and frustration RK experienced with the Challis instruments. Later, RK began using instruments built by William Dowd, a former assistant to Challis.

February 27, 1934

My dear Mr. Challis,

I am eagerly looking forward to making the acquaintance of your harpsichord in the Dessof Concert of March 16. I was very much pleased at the ottavino and the clavichord (except for the steel strings) which I saw recently in New York. It is a tremendous encouragement to me to know that someone is carrying on in this country instrument-building of the Dolmetsch quality.

If you could send me some information about the instruments you have built and your plans for further construction, I should be intensely interested—and perhaps able to instigate some orders.

If it is possible for the harpsichord to remain in New York, I should very much like to use it for several concerts later in the month, one for the League of Composers (the de Falla Concerto) and for the first New York harpsichord performance of the Goldberg Variations, probably to be sponsored by the New Music School, perhaps also by the David Mannes School. Of course, I shall be only too delighted to give to your work all the publicity I can.