Editing Music radio (section)

===Commercial radio===
Commercial stations charge advertisers for the estimated number of listeners. The larger the audience, the higher the stations' rate card can be for commercial advertising.

Commercial stations program the format of the station to gain as large a slice of the demographic audience as possible.

A station's value is usually measured as a percentage of market share in a market of a certain size.  The measurement in U.S. markets has historically been by [[Arbitron]], a commercial statistical service that uses listener diaries.  Arbitron diaries were historically collected on Thursdays, and for this reason, most radio stations have run special promotions on Thursdays, hoping to persuade last-minute Arbitron diarists to give them a larger market-share.  Stations are contractually prohibited from mentioning Arbitron on the air.

Market share is not always a consideration, because not all radio stations are commercial. [[Public radio]] is funded by government and private donors. Since most public broadcasting operations do not have to make a profit, no commercials are necessary. (In fact, because most public broadcasting stations operate under noncommercial licenses from their country's broadcasting regulator, they may not be allowed to sell advertising at all.) [[Underwriting spot]]s, which mention the name of a sponsor and some information but cannot include "calls to action" attempting to convince the listener to patronize the sponsor, may be allowed.

Also, [[satellite radio]] either charges subscribers or is operated by a public broadcasting service. Therefore, satellite radio rarely carries commercials or tries to raise money from donors. The lack of commercial interruptions in satellite radio is an important advantage. Often the only breaks in a satellite music station's programming are for [[station identification]] and DJ introductions.

[[Internet radio]] stations exist that follow all of these plans.

Much early commercial radio was completely freeform; this changed drastically with the [[payola]] scandals of the 1950s. As a result, DJs seldom have complete programming freedom.  Occasionally a special situation or highly respected, long established personality is given such freedom. Most programming is done by the program director.  Program directors may work for the station or at a central location run by a corporate network.  The DJ's function is generally reduced to introducing and playing songs. Many stations target younger listeners, because advertisers believe that advertising can change a younger person's product choice.  Older people are thought to be less easy to change.

Music radio has several possible arrangements. Originally, it had blocks of sponsored airtime that played music from a live orchestra.  In the 1930s, phonograph records, especially the single, let a [[disc jockey]] introduce individual songs, or introduce blocks of songs. Since then, the program has been arranged so that commercials are followed by the content that is most valuable to the audience.

Programming is different for non-traditional broadcasting. The [[Jack FM]] format eliminates DJs entirely, as do many internet radio stations. The music is simply played. If it is announced, it is by [[Radio Data System|RDS]] (for FM broadcast) or ID3 tags (for Internet broadcast). Satellite radio usually uses DJs, but their programming blocks are longer and not distinguished much by the time of day.  In addition, receivers usually display song titles, so announcing them is not needed.

Internet and satellite broadcasting are not considered public media, so treaties and statutes concerning obscenity, transmission of ciphers and public order do not apply to those formats. So, satellite and internet radio are free to provide sexually explicit, coarse and political material.  Typical providers include [[Playboy Radio]], uncensored [[hip hop music|rap]] and [[hard rock]] stations, and "outlaw" [[country music]] stations.

The wide reach and selective, non-broadcast usage of the internet allows programmers access to special interest audiences. As a result, both mainstream and narrow-interest webcasts flourish; in particular, electronic music stations are much more common on the Internet than they are in satellite or broadcast media.