Columbia subject headings:
Music and technology--History--Congresses.
Music--Acoustics and physics--History--Congresses.
Musical instruments--History--Congresses.
Sound--Recording and reproducing--History--Congresses.
Harvard subject headings:
Electronic musical instruments--History.
Princeton subject headings:
Music and technology--History--Congresses.
Music--Acoustics and physics--History--Congresses.
Musical instruments--History--Congresses.
Sound--Recording and reproducing--History--Congresses.