“Music Publishing” is the owning and exploiting of musical copyrights. There are many types of “rights” within a “copyright” that can be exploited. One can license the reproduction of sound recordings such as CDs, tapes and records. One can license public performance of a song. Songs may be “synchronized” with visual images in movies and television shows. They can be incorporated into advertising, karaoke programs, ringtones, samples for other songs, greeting cards, toys, video games, internet uses and more. And of course, songs can also be exploited and sold as written sheet music.
The music publisher controls all of these rights with respect to a given use. In short, music publishers are really “rights holders and licensors.”