informator choristarum
/ˌɪnfɔːˈmɑːtə ˌkɒrɪsˈtɑːrəm/ /ˌɪnfɔːˈmɑːtɔː ˌkɒrɪsˈtɑːrəm/noun
A choirmaster, a musical director. Now historical exc. as the title of the director of the choir of Magdalen College, Oxford.
Origin
Mid 17th century. From post-classical Latin informator choristarum from informator + choristarum, genitive plural of chorista.