These are companies like ASCAP, BMI, SESAC, etc.
Performing Rights Organizations are responsible for collecting income on behalf of songwriters and music publishers when a song is publicly broadcast. Public performances can include play in television, radio, clubs, restaurants, websites, or other broadcasting systems. PROs collect fees from these establishments which they then pay to their registered songwriters or their publisher.
Each territory worldwide has one or more performing rights organization, responsible for collecting performance royalties for that specific territory. When you join Songtrust, we register your songs directly with PROs around the world to collect your royalties directly from the territories in which they were generated. This gets you paid more quickly and with more detailed royalty statements.
PROs do not collect mechanical royalties generated from sales/streams. In order to collect those, you must be registered with a mechanical collection society, such as the Harry Fox Agency.
All writers must be affiliated with a PRO in order to receive their writer's share.