You decide:

DJ= Disc Jockey

Disc Jockey (Dictionary.com definition):

–noun
1.
a person who conducts a radio broadcast consisting of recorded music, informal talk, commercial announcements, etc.

2.
a person who selects, plays, and announces records at a discotheque.

Musician (Dictionary.com definition):

–noun
1.
a person who makes music a profession, esp. as a performer of music.

2.
any person, whether professional or not, skilled in music.