The proposition is entirely correct: organs (and all instruments)
should play good music, and there's plenty of good modern music, so
they should include it.  There are several top-notch arrangers and
organs showing how it can be done, although I've also heard a few
examples of how not to do it.

There are always some organs at the Dorset Steam Fair playing new-ish
music, notably the two large Johnny Verbeeck concert organs "Centenary"
and "Victory" whose crisp playing and repetition allow them to do
modern pop music very effectively.  Maybe the translation in musical
format isn't always wholly successful or as lastingly-satisfactory as
some of the more complex older music, but it certainly makes it hard to
think of the machines as outdated relics.

Last year "Victory" was accompanying pop videos projected onto a large
screen; I admired the bravery of all concerned in trusting all that
equipment to an English summer!  It's a commercial venture rather than
preservation, and that clearly affects the choice of repertoire, which
is explained on its web site

  http://www.victoryontour.com/content/view/9/10/lang,en/ 

The latest CD includes themes from Pirates of the Caribbean and Harry
Potter, which seems to me an astute choice of truly-contemporary music
likely to work well.  You can download clips from the web site, or find
then on YouTube.  Well worth having a look.

When I have heard failures, they have been flat renditions of popular
material that has tried to translate it into an older style and
succeeded in being neither.  Making new music old-fashioned is rather
missing the point!  The YouTube clip of Altobella Furiosa in Waldkirch
shows exactly how to match style and content, and present the whole
thing with verve.

Julian Dyer