In most cases, CMOs are not-for-profit entities. They manage music rights for authors, performers, producers and other right holders to simplify the management of those rights. Some of the services they offer:
monitor the use of when, where and what works are used;
negotiate tariffs and other conditions with users;
license the use of protected works on behalf of its members and of other rights holders it represents; and
collect the fees from users and distribute these to the rights holders.
Depending on the repertoire they represent, they can also be called:
Music Licensing Companies (MLCs)
Mechanical Rights Organizations (MROs)
Performers’ Collective Management Organizations (PMOs)
Reproduction Rights Organizations (RROs)
source: WIPO