Usually, when Amnesty International is in pursuit of the spare change in the pockets of the nation's youth, it goes after the university- dwelling, middle-class rock-music-orientated white teenager, who stumbles the charity's way at a festival like Glastonbury. But the gig at which hip-hop young bloods Structure Rize play is altogether different.

To mark the 37th anniversary of Amnesty International, there is a benefit gig night featuring a line-up of burgeoning British R'n'B and hip-hop. All participating bands, as well as the audience, will be asked to put their signatures to the "Get Up, Sign Up" campaign, backing Amnesty's Declaration of Human Rights. The targeting of black youth is perhaps long overdue - even rapper D Grim of Structure Rize is unaware of Amnesty International's history:

"I have never heard of it, but we are glad to be part of it if it's helping human rights, you know," he reasons. "Everybody wants to have the right to do what they wanna do, and we are honoured to be asked. I am interested in politics, but I am not really a political guy, and, well, only write about it as the music progresses."

As a UK-based crew, the Brixton based Structure Rize have a fair job on their hands to secure even a smidegeon of chart success. That revolution in attitudes among British hip-hop fans and record companies - support for homegrown rap - has threatened to occur a good few times in the past decade, but never quite happened, disappointingly. But songs like the recent single from Structure Rize - Da Jonsez - with its rough cut, Wu Tang Clan vibe, deserve attention. Importantly, it takes a major label with the cash and the commitment to see the artists through - have Structure Rize got that? "They have been fairly supportive, we are not complaining, but we are not a pop group, and you cannot anticipate a pop reaction from a non-pop group. But we have now made an album that the record company can be satisfied with, and made stuff to keep it real with the underground, because that's where we're coming from."

Holding up the R'n'B end of the Amnesty bill are Truce, while the well respected hip-hoppers Blak Twang also put in an appearance, along with folk who Structure Rize worked with last year, Damage.

"Structure Rize are going to tear it down, d'you understand?" whoops D Grim, knowing the band have tough competition that night. "We are going to make the party correct."

Mean Fiddler, Harlesden, NW10 (0181-961 5490) 25 May. For more on Get Up Sign Up, see After Dark, pages 52-53