Columbia subject headings:
Music trade--Great Britain--History.
Music trade--United States--History.
Sound recording industry--Great Britain--History.
Sound recording industry--United States--History.
Harvard subject headings:
Music trade--Great Britain--History.
Music trade--United States--History.
Sound recording industry--Great Britain--History.
Sound recording industry--United States--History.
Princeton subject headings:
Music trade--History.
Sound recording industry--History.