Five gang members who made "drill" music videos glorifying violence have been sentenced after being caught with machetes and baseball bats.
Micah Bedeau, 19, Yonas Girma, 21, Isaac Marshall, 18, Jordan Bedeau, 17, and Rhys Herbert, 17, were jailed or detained for conspiracy to commit violent disorder, in Notting Hill.
Police also applied for a court order to stop the group making drill music.
Drill is a dark form of urban dance music often featuring violent lyrics.
It originated in south Chicago and is derived from "trap" music, which is noted for its bleak atmosphere and references to drug dealing. Performers have also been accused of misogynistic content.
Officers caught the gang "red-handed" on 9 November 2017 after a two-year anti-gang operation.
The members of the Ladbroke Grove gang, 1011, were thought to have been about to attack rivals from the 12 Worlds gang from Shepherds Bush.
Kingston Crown Court heard that the attack was in retaliation to a YouTube video posted by 12 Worlds of the grandmother of the Bedeau brothers being harassed.
Jurors were shown seven YouTube videos of the gang wearing balaclavas and full-face masks.
The footage, which has since been removed, featured sounds of gunshots and lyrics glamorising violent crime.
Jurors heard that the long-established major UK label Polydor Records had offered to work with the group.
The court was told that music videos made by the gang members had been watched more than 15 million times online, and that they had earned thousands of pounds from music streaming sites.
Before pleading guilty, the gang insisted the weapons they were caught with were simply props to be used in a new music video.
Det Ch Supt Kevin Southworth, of the Metropolitan Police, said: "When in this instance you see a particular genre of music being used specifically to goad, to incite, to provoke, to inflame, that can only lead to acts of very serious violence being committed, that's when it becomes a matter for the police.
"We're not in the business of killing anyone's fun, we're not in the business of killing anyone's artistic expression - we are in the business of stopping people being killed."
The Met asked the judge, Recorder Ann Mulligan, to consider applications for Criminal Behaviour Orders (CBOs) to be handed to the gang to stop them from making any more drill music. This decision has been adjourned to a later date.
Ms Mulligan said there was "undeniably real musical talent on display" in the videos and that a "potentially promising music career" lay ahead of the defendants.
But she added that much of the content was "menacingly violent" and showed "truly appalling attitudes to women".
She said she was certain "serious violence would have ensued" if the men had not been arrested.
YouTube recently deleted just over half of the music videos that the Met Commissioner, Cressida Dick, said were inciting violence.
The Met has built up a database of more than 1,400 videos to use as an intelligence tool.
The force is tackling a recent rise in killings and other violent crime, with more than 70 murder investigations launched already this year.
Speaking about the spread of drill music in the UK, an academic said it gave an insight into the needs of deprived young people, rather than simply glorifying violence.
Criminologist Dr Anthony Gunter told the BBC: "If you see violence and pain and suffering all around you, because you live in a deprived neighbourhood, you're going to make music that's intense, violent and painful.
"If we want them to make beautiful music - nice, kind music - we've got to invest in these urban communities."
Micah Bedeau, 19, of Colville Square, Notting Hill - three years and three months in a young offenders' unit
Yonas Girma, 21, of Hounslow Road, Hanworth - imprisoned for three years and six months
Isaac Marshall, 18, of Ladbroke Grove - two-year detention order
Jordan Bedeau, 17, from the W11 area - one-year detention and training order
Rhys Herbert, 17, from the W11 area - one-year detention and training order