Broadcasting, in the context of music licensing, means the playback of recorded or live music for groups of people beyond what might be normally expected in a social setting. Legal claims are filed frequently against bookstores, bars, and live music venues that broadcast music without first obtaining a performance license.
The music broadcast in grocery stores and elevators is a service purchased from one of many organizations that offer it (the largest is Muzak). Part of the fee paid for the service is used to cover licensing costs. Except in very narrowly defined circumstances, noted below under the "small business exception" in 17 USC 110, a business, restaurant, or store that plays radio broadcasts or shows TV programs in the premises does not pay a licensing fee.
Radio stations pay fees to licensing bodies for nonexclusive rights to broadcast music. Radio stations and businesses typically pay a flat rate once a year, called a blanket license, which can vary based on the size of the audience, value of the advertising revenues, and amount and nature of music usage. As part of the license contract a radio station may conduct periodic audits of the music being played, with the audit results submitted to the licensing body.
Broadcasting pre-recorded music at live events at outlets larger than stores or restaurants, such as stadiums, arenas, or parks, is covered under United States Copyright law through a "blanket license" that obtained from one of the performing rights organization (PRO), such as BMI or ASCAP. These are compulsory licenses that are held by the PROs, and typically offered based on a per-attendee cost per song, paid to the PRO, which then distributes the royalties to the artists.[8]
In 2012, both BMI and ASPAC introduced a new type of blanket license for political-based events such as campaign rallies called a "Political Entities License". While similar to the blanket license for broadcast of pre-recorded music at large public events, it gives the artists the ability to disallow the use of their music for specific political functions.
Source: https://en.wikipedia.org/wiki/Music_licensing