ASCAP (American Society of Composers, Authors and Publishers) and BMI (Broadcast Music, Inc.) are performance rights organizations that license and collect royalties for the public performance of musical works on behalf of their songwriter and publisher members. For example, when a song you've written is played at a bar or over the speakers at Target, you're owed Performance Rights royalties. They distribute these royalties to their respective members after deducting operating costs.
If you’re interested you could join either ASCAP here or BMI here (Can’t join both), to ensure you properly collect your performance royalties.