What is the X in X-mas?
"master of music, great teacher or composer," 1797, from Italian maestro, literally "master," from Latin magisterium, accusative of magister (see master (n.)). Applied in Italian to eminent musical composers. Meaning "conductor, musical director" is short for maestro di cappella (1724), literally "master of the chapel" (cf. German kapellmeister).
A title for distinguished artists, especially those in music. It may be given to teachers, composers, conductors, or performers. Maestro is Italian for “master.”