A few years ago it was still common for horns and trumpets to see parts in various keys - C trumpets, Eb horns, etc. The ease of producing 'standardized' parts in music notation programs has made this much less common, and even when renting orchestral stuff you get the option of transposed parts or the originals.

Still a good practice for someone looking to be a performance major to be able to do it. Universities and symphonies aren't going to spend money to update their libraries so that the horns and trumpets don't have to transpose.

I would expect an orchestral excerpt of some kind - maybe an orchestral solo that is in another key.