Camille Saint-Saens' "Le Cygne" (The Swan) from The Carnival of Animals, arranged for 2 cellos by Eric Moore. 

The second part is an accompaniment intended to be used instead of piano - it is lush and beautiful.

Also look for the other standard French Showpieces arranged for 2 Cellos as a digital download!
Allegro Appassianato | Apres un Reve | Elegy | Papillon | Sicilienne