Who is Achille Papin in Babette's Feast by Karen Blixen?

Achille Papin is a world reknown French opera singer. He is mesmerized by Philippa's voice and wants to give her private lessons in order to ready her voice for the stage. Philippa chooses not to pursue her singing career after Papin kisses her during one of their sessions. As a result, she choose to focus herself on her father's congregation. Her work is in the church.