I love listening to or watching Giselle, and my ear gets used to the melodies for various parts. Recently I was surprised by a change in the melody for Albrecht's entrance in Act 2. Usually it is an oboe solo, but the oboe had been replaced by a cello, and the melody sounded as though it might have been harmony for what I had thought was the original.
Can anyone explain where the cello and different melody might have originated?