There are 2 potential candidates I am aware of, Igor Stravinsky wrote a piece called Pastorale and Beehovens 6th Symphony is also called the "Pastorale Symphony". Interestingly enough both that and Beethovens 5th symphony were both first performed on the same night with Beethoven opting for his gentler and more serene 6th played first to prepare the audience for his more intense 5th symphony.