Sections of pipes working independently from the main keyboard are
found in many types of mechanical organs.  In American band organs,
derived from German (Gebr. Bruder) fairground organs, this section
is almost always worked by trumpets only.

In other organs, like the French Gaviolis, the Belgian dance hall organs
and many Dutch street organs, the countermelody section is used for
a large variety of pipe registers, all which have one thing in common:
they sound about an octave lower than the normal "melody" section of
the organ, and they may be used together with this melody section.

The name countermelody is somewhat confusing; the prefix counter- is,
musically speaking, referring to an exaggeration more than to an
opposition.  A counter-tenor is a tenor (usually from British origin)
who has learned to sing about an octave higher than an ordinary tenor,
while a contrabassoon plays an octave lower than a normal one!

Regards,
Hans van Oost, Netherlands

 [ The Dictionary of Musical Terms, 23rd Edition, 1923, says:
 [
 [   contra (from Latin & Italian): Compounded with names of
 [   instruments, it signifies an octave below, e.g., contrabasso,
 [   a double-bass; contraviolino, a double-bass viol.
 [
 [ The female contralto voice follows this definition ('below alto'),
 [ unlike the countertenor who is 'above tenor'.  -- Robbie