Faking the Duo-Art

Greetings MMDigesters,  The suggestion of using a couple of accordion
sets to interpret Duo-Art expression codes makes little sense.  The
position of the regulating lever at any given moment is but one
contributor to the total system.

The Duo-Art is very unusual piece of engineering, if you can call it
that at all.  It produces excellent music, not because of the regulating
system, but in spite of it.  The editors had their hands full getting
that beast to cooperate and must be thanked profusely for the beautiful
music they produced.

In addition to the position of the regulator lever, you need to
consider several dynamic variables that can not just be derived from
a simple mathematical mapping of regulator position to loudness.  Even
a complex mapping of all possible static combinations will not do as it
is the relationships with respect to time that determine how the system
responds.

Some contributors to the Duo-Art expression include the following:

1. Note droop, both short term and sustained.  This is very important
on the Duo-Art and no model that does not take account of this will
come close to sounding like one.

2. Theme valve activity including the use of the captive theme
regulator volume and other peculiarities of the theme system.

3. Spill valve cross regulator coupling effects.

If these are not considered, the quality of the emulation will vary
according to the coding techniques used for a particular roll.  Some
will emulate well enough but others horribly and the subtle effects
that make Duo-Art music remarkable will be totally lost.

Best regards,
Spencer Chase
Garberville, CA
http://www.spencerserolls.com/