Seventy Eight Edit Meaning

1.

A sound recording, in disc form, usually made of a shellac compound, which plays at a speed approximating 78 revolutions per minute (later exactly at 78.26 rpm) and manufactured between 1889 and 1968 (with rare exceptions--dates for the US are 1892-1958)

I have an old seventy-eight of Glenn Miller my father used to own before the war