How are the voices of marginalised and disadvantaged communities to be heard in a large conurbation? This article argues the importance of community media, and particularly community radio, in providing such communities with opportunities to express their cultures and concerns. Its main focus is London, whose size and geography pose special problems for broadcast coverage, but comparisons are made with other European capital cities – Budapest, Cardiff and Stockholm - and the historical legacy of London’s problems, which has defeated other attempts in the past to use radio to meet the needs of London communities, is briefly summarised. The research which is reported is ongoing; at the time of writing a series of media policy workshops is being planned with the hoped-for involvement of the London Mayor’s office and of local authorities. Policy interventions are never final, so this is an account of work in progress.