Columbia subject headings:
Harrison, G. Donald (George Donald), 1889-1956--Correspondence.
Organ (Musical instrument)--United States--History--20th century.
Organ builders--England--Correspondence.
Organ builders--United States--Correspondence.
Skinner, Ernest M.--Correspondence.
Willis, Henry, 1889-1966--Correspondence.
Harvard subject headings:
Organ (Musical instrument)--Construction
Organ (Musical instrument)--United States.
Organ builders--Correspondence.
Princeton subject headings:
Harrison, G. Donald (George Donald), 1889-1956--Correspondence.
Organ (Musical instrument)--United States--History--20th century.
Organ builders--England--Correspondence.
Organ builders--United States--Correspondence.
Skinner, Ernest M.--Correspondence.
Willis, Henry, 1889-1966--Correspondence.