There is a real difference between expressing one's views and urging others to commit murder... a real BIG difference.

In theory, speech may not be suppressed or punished -- BY THE GOVERNMENT -- unless it is intended to produce "imminent lawless action" and it is "likely to produce such action." Otherwise, the First Amendment protects even speech that advocates violence. This is known as "the Brandenberg test" and is the law today. It is a two-prong test which requires: (1) Intent, and (2) Likely To Produce "imminent lawless action."

In the case of Sizzla, even his most offensive, hateful song lyrics would be unlikely to qualify. Maybe you could argue that he had the intent, but the likelihood of its actual immediate occurrence seems exceptionally slim.

On the other hand, consider the words spoken to a large crowd in Jamaica in 2004: "they urged the audience to 'kill dem, battybwoys haffi dead, gun shots pon dem. Who want to see dem dead, put up his hand'" [note: it is not clear from the Amnesty Intl report precisely who spoke these words; it may have been Capleton, rather than Sizzla.]

Where a speaker is directly urging a crowd to engage in violence, then we likely reach the first prong of "intent to cause imminent lawless action."

The second prong would require us to determine the likelihood that such actions would occur as a result of the speech. If there were no "openly gay" people at the concert, then the likelihood would probably be low. Whereas, if there were a group of gay protesters nearby, then the speech could reaonably be construed to have both the intent AND the likelihood of causing imminent harm. At that point, in the US, the government could legally intervene...

But again, that is all about _government_ prohibitions upon individuals' speech. That is totally different than private persons urging other persons and businesses to not support nor promote a particular viewpoint (in this case, one which encourages murder of queers).

Urging individuals to not support hatred is NOT censorship.

Urging businesses to not support, promote and/or profit from hatred is NOT censorship.

Threatening to picket/boycott businesses that support, promote and/or profit from hatred is NOT censorship.