Paul Whiteman decided to take the CONCERTO on tour in 1928.  It was
obviously impossible to travel with the 100 or so players that the immense
score required, so Whiteman turned once more to Ferde Grofe.  Grofe scaled
the orchestration down so that the 30 piece band could handle it, adding
saxophones in the process to replace several of the symphonic winds.

So, Steve, if you want to verify this data, and listening this other
interesting version, just buy the ProArte CD mentioned in my first post.

Another comment: this CONCERTO version was recorded on 3 discs by
Columbia in 1928 with Roy Bargy playing the solo piano.

Keep in touch!

PS.- If somebody is interested in The Gershwin Facsimile Editions or
Orchestral Study Scores, Gershwin Ensembles, Etc.  there is an interesting
site:

   http://www.burtnco.com/WarnerBros/gershwin2_centennial.htm

Dave.
Guadalajara.