Transposing music between oboe and clarinet isn’t terribly difficult. It’s just not nice when it’s unexpected, at 8 AM, and for a concert in less than 48 hours.
We actually played the first movement of Schubert’s Unfinished Symphony (really pretty! go find it and listen). LOTR came later in the semester.
http://www.youtube.com/watch?v=3ySpn8E-dAE