To the point, Johann Sebastian Bach had exactly eight professions during his life: he played music, so he was musician. He has composed music plus he was choir leader, concert master and band leader. In addition he was teacher, he played the organ in Arnstadt and Muehlhausen as an organist and in Leipzig he organized the whole church process as the Thomas Cantor. During his whole life he was an organ expert too.
99 Music Calendars, Composers Calendars and Bach Calendars