Hi Ralph,
Yes, you can rotate the entire score and get landscape printing, but your printer also has to understand that
For the Composer side, you can use Format/Page Setup to set up a landscape-orientation format for any (or all) part(s).
Most printers will understand this, and just print the score landscape. However, I used to have an HP printer that for some reason had to be independently set to whatever the orientation was that I had selected in my program (any program - totally frustrating). Is this perhaps the case with your printer, that you also have to select "Printer properties" (or whatever it's called for the particular printer) and set it for "Landscape"?
I print out all my Conductor's Scores in landscape orientation, and it works for me (Canon printer).
ttfn,
Sherry