After the debate about Solenoid vs. Pneumatic Pianos, some of us
concluded that pneumatic pianos offer better performance, and would
be ideally equipped with electronic control.

Such a control device has been developed by Broadmoore Research
Corporation of California.  This device will give you the noted
convenience of the solenoid pianos, with an increase in your piano's
performance.

The new Tracker Bar Interface (TBI), is a compact electro-pneumatic device
which fits in the spoolbox of any pneumatically actuated instrument
(player piano, reproducing piano, orchestrion, band organ, etc.) which
uses a pneumatic tracker bar.  Adjustable arms have sockets which engage
the roll chucks, and a silicone rubber gasket seals against the tracker
bar, making a tight seal to each hole.

The mounting plate, or chassis of the unit, contains a labyrinth of
passageways between each tracker bar port and a light steel valve plate,
faced with silicone rubber, which normally is held closed by a beryllium
copper spring.

Positioned at each valve is a small magnet which, when energized,
attracts its valve open, thus admitting atmospheric air into the
passageway leading to its tracker bar hole.  Therefore, energizing any
note magnet is functionally identical to the appearance of a perforation
on a music roll, over a tracker bar hole.

Music rolls, which have been transcribed to data files, can be sent to
the TBI via its MIDI cable.  The electronic signals actuate the magnets
which open the tracker bar holes, thus operating the piano.  Expression
data operate the tracker bar magnets the same way as note data, and open
the appropriate ports to produce dynamic expression as intended by the
manufacturers of the system being actuated.

Several distinctive features should be noted:

1. The device is so made as to enable the roll compartment on most
instruments to be closed when it is installed, thus completely concealing
it from view.  This is due to the fact that its machinery occupies the
space normally occupied by the roll.

2. Tests on dozens of different spoolboxes, including orchestrion
spoolboxes, showed that the device adapted easily to fit all of them.

3. This unit is quite self-contained, having its electronics mounted to
the magnet valve unit.  Therefore, only two thin wires: a telephone-type
signal wire, and a low voltage power wire from an AC adapter, plug into
it.  Installation and removal can be done in seconds.  It is "non-
invasive" and does not disturb the authenticity of any instrument.  Not
a single fastener is needed to install it; it is installed and removed
precisely like a music roll.

4. The wind motor is not needed with this device and is left shut off when
the device is in use; therefore the (rather considerable) vacuum normally
used to propel the roll, is available to the rest of the mechanism of any
instrument.  (This is especially helpful on instruments which are weak due
to needing service.)  Any musical timing errors due to mechanical
imperfections in the roll transport system, which are extremely difficult
to completely eliminate, and which vastly affect the quality of musical
performance (imperfections either built in by the manufacturer, resulting
from deterioration of parts, or due to poor restoration), are entirely
eliminated.  All spoolbox noise is eliminated, since there are no moving
parts except for the rubber-cushioned note valves.  (The unit itself is
silent.)

5. Long experience with the Stahnke Cassette Converter (CC-3) shows that
notes actuated by electric valves tend to operate better than when
operated by a music roll.  The perforation on a roll gradually uncovers a
hole, whereas the valve's operation is sudden, providing hysteresis.
This gives far better note articulation and repetition, especially when
the bleed-to-atmosphere ratio is incorrect, which is so often the case.

6. A disc-drive controller will be available which will provide data to
the piano, for those who don't want to bother with a computer.  It will
have an optional remote control, providing unlimited hours of music at
the touch of a button.

7. If electrically pumped, an optional relay can be installed, such that
the software will automatically turn the piano's motor on at the
beginning of each selection and off at the end.  Energy expenditure,
waiting, and wear during rewind are eliminated, since rewind is
unnecessary.  On pianos not equipped with automatic rewind and shutoff,
these functions are no longer of concern, nor is the danger of a roll
coming detached from its spool if rewind is not manually initiated in
time.

8. Expression can be added to selections digitally played on foot-pumped
instruments by pumping, in the usual way.  In the future, a video display
will be available, to show words and expression lines.  Other features,
as well, are planned.

9. Scanned music rolls can be corrected for a myriad of errors due to
roll warpage, expansion and contraction due to climatic variations,
perforator wear and other defects, editing carelessness and other clearly
mathematically detectable problems.  Therefore, when scanned and edited
competently and meticulously, they have the potential to play far, far
better than they ever did in paper form.

10. The wasted time and bother occasioned by music rolls: roll damage,
roll storage, rewinding of rolls, alignment of the music sheet to the
flanges before using, tracking problems, dust and punchings from rolls
being sucked into the bleeds, spoiling of the mood of the music while
rolls rewind, the heartbreak of watching cherished rolls disintegrate
from age, etc...  All of this we happily consign to the ash-heap of
history.  But the joy music rolls bring to us through their music --
this we shall multiply, disseminate and secure forever.


The TBI can be ordered from Broadmoore Research Corporation for $1495,
on an 8-week delivery basis.  Please contact Larry Broadmoore with any
questions at  larrybr3@loop.com .

Laurent Coray

 [ Editor's note:
 [
 [ Both Larry Broadmoore and Laurent Coray are MMD members, and I think
 [ they would welcome a technical discussion on these pages.  Laurent
 [ has designed the electronics potions of the system based upon his
 [ experience with the UM-1 MIDI adapter unit.
 [
 [ Larry's valve design is derived from the Duo-Art Concertola valve,
 [ which had to work properly at all suction levels encountered in a
 [ Duo-Art piano.  It's very compact.
 [
 [  -- Robbie