This class covers all sound-emitting devices, in general, whether or not they may be considered as being musical.
In this class, the following expression is used with the meaning indicated:
"musical instrument" does not exclude devices emitting a single sound signal.
The following Class Index is given in place of subclass indexes, to show the grouping of the elaborations belonging to different subclasses, under the following three fundamental types:
wind instruments;
string instruments;
percussion instruments,
which relate clearly to the majority of instruments.
This subclass covers musical instruments in which individual notes are constituted as electric oscillations under the control of a performer and the oscillations are converted to sound-vibrations by a loud-speaker or equivalent instrument.