Music censorship

Music censorship refers to editing, censoring or changing different forms/areas of music for a particular reason. The reasons for censoring or editing a song often include moral, religious or political subjects or themes involving the song in question. Censorship often varies from the complete government-enforced legal prohibitions for musical works to the optional removal of questionable or inappropriate material when a song or other musical work appears in a particular context.
Decency.
Songs are often edited before they're broadcast on any radio or television networks. This is for removing any material that may be classified as objectionable for a number of listeners. The objectionable materials in question include profanity, references to sex, violence and drug abuse/trafficking. This is mainly done to comply with the relevant rule in broadcasting and with the conduct codes. It's also done for making songs more marketable for mainstream audiences. Songs edited for materials within this manner are mainly called clean version songs. Common editing techniques include backmasking, blocking or completely replacing any offensive lyrics with different words.
Examples of songs with questionable or offensive words.
Several different edits of the CeeLo Green pop/soul song "Fuck You". These include one where the song's lyrics and title were changed to "Forget You." Another mutes the profanity "fuck" without actually replacing it. The original title for The Black Eyed Peas' 2003 song "Let's Get it Started" was "Let's Get Retarded". The song's title was changed because the word "retarded" was an offensive word. "Let's Get it Started" was later released as a standalone single. It peaked at #21 on the United States' "Billboard Hot 100".
Songs having possibly objectionable wordings with double meanings or mishearings of certain phrases were also sometimes censored. One example for such songs includes Britney Spears' 2009 dance-pop single "If U Seek Amy". The chorus and title for this Spears' song were heard in the words "F-U-C-K me". Spears' then record labels made a radio edit of the song in which the word "seek" was replaced by "see". That was because "If U Seek Amy" was criticized for being a sexually offensive song. The song caused serious controversy related to possible obscenity all across the world. Similar concerns and troubles happened with The Black Eyed Peas' 2005 single "Don't Phunk with My Heart". Radio stations were especially worried the word "phunk" (the misspelling of the word "funk") could be misheard by listeners as sounding almost like the word "fuck". The group's record label created an alternate version changing the word to "mess".
Criticism.
Some listeners have not been satisfied with musical works being edited for being played over radio. They say that it damages the artistic integrity of the original song. Listeners have to seek out other platforms which are not being censored. One example of such platforms is listening to music through the Internet. The gangsta rap group N.W.A was highly controversial, in particular for the song "Fuck tha Police", released in 1988. The assistant directors of the Federal Bureau of Investigation sent letters to Priority Records to protest against the lyrics of the song. In 1992, another song about violence towards law enforcement agents, "Cop Killer", was released by Body Count and rap singer Ice-T. 
The civil rights activist C. Delores Tucker criticized gangsta rap. She was intensely criticized during several songs over her having negative opinions toward gangsta rap. One especially criticizing song was the 1996 Tupac Shakur song "How Do U Want It". Tucker sued Shakur's estate for emotional distress and slander related to the song. The lawsuit, however, was later dismissed.
In 1990, Floridian political activist Jack Thompson targeted Miami-based rap singers 2 Live Crew and their 1989 album "As Nasty as They Wanna Be". Songs on the album included "Me So Horny" (taken from the 1987 war movie "Full Metal Jacket"). Thompson classified the rap album as obscene.