Masonic music has been defined as "music used in connection with the ritual and social functions of freemasonry." Two major types of music used in masonic lodges are lodge songs, played to keyboard accompaniment before or after meetings, or during meals; and music written to accompany specific masonic ceremonies and events. Because the number 3 and the letter 'B' are of particular significance to freemasonry, music written in the keys of C minor or E flat major, which both involve 3 flats,, in their key signatures has been considered especially appropriate for masonic ceremonial music.