Allen Organs and Stretch

[Robert Scott]

John Elving wrote:

>  Just a couple of weeks ago I tuned a church piano that they wanted tuned to
>their new excellent quality electronic organ (Allen). When I checked out the
>A4 on the organ, I discovered that two of the three keyboards were identical,
>(4 cents sharp), but the third manual was 7 cents different than the other
>two. They had to make some quick phone calls to have acommittee meeting to
>decide which A they wanted the piano tuned to. Democracy ruled - 2 out of 3
>keyboards wins!

  I seem to recall measuring the pitches of an Allen digital organ a number
of years ago. I was surprised to find that it had some designed-in stretch.
Does anyone know how they decide how much stretch a digital organ
should have?  They obviously don't need to worry about inharmonicity.
Perhaps they are trying to make the Allen correspond a little more with
pianos for when they are played together?

   -Bob Scott
   -Ann Arbor, Michigan