A free way to view expensive scores
Through networking with other music educators I have recently discovered a couple of places online where contemporary orchestral scores can be viewed. This is very useful as it can often be difficult to provide inspiring material for the musical commentaries and analyses that are required in the advanced music courses. These resources are also be very useful when teaching contemporary music as visual examples of different musical concepts could be obtained from here.
Boosey & Hawkes
By creating a profile on Boosey & Hawkes' webpage you instantly get access to over 1000 online scores. Obviously these cannot be downloaded but it is still a very useful way to view and discover scores which would otherwise be prohibitively expensive. For example, contemporary orchestra scores such as James MacMillan's A Scotch Bestiary: enigmatic variations on a zoological carnival at a Caledonian exhibition... an amazing piece!
Scores for Online Perusal
Slightly less mainstream, but useful nonetheless, is Scores for Online Perusal which is part of Theodore Presser. This is essentially the same idea but the composers and works are less well known. However, there are a few works by Charles Ives, one of which is Putnam's Camp which is excellent for highlighting bitonality!