During a trip to buy a big Aeolian residence organ, I discovered the
answer to the mystery of what the five Aeolian LCW holes stood for.
Some big organs with 71, 65, and 88 ranks were surveyed, and old test
rolls were found in a closet, along with a few scraps of old paperwork.
Unrolling the test rolls revealed the information. The five holes were
coupler control holes for other divisions in really big organs.
Hole 171 seemed always intended to couple the Echo organ to either the
Swell or the Great. Which one probably depended on what the rank
complement of the Echo organ contained and the acoustic setting for
that division. Some organs had really large Echo divisions, others had
the expected three ranks plus the inevitable chimes, and occasionally a
Holes 164-165-173-174 coupled the divisions listed on the test roll:
Solo, Vibrato, String, Ancillary Great, Orchestral, Percussion, and
Antiphonal. One suspects that they were custom wired for the specific
organ. Nothing was listed on how the stops were to be controlled, only
the playing notes. But it is not hard to see that perhaps the stops
were parallel-wired to the same stops in the main organ divisions, or
perhaps left up to the organist's choice. Custom wiring seemed to be
LCW was a quip to Nelson Barden years ago: "Let's Confuse Welte." I
like "Lower Control Widget" too.