Rap songs from Public Enemy and Ludacris have been heard at marches over the killing of George Floyd. But the history of Black American music as a form of protest dates back to the 19th century.
Over the past 50 years, protesters' voices have found power in unison. But activists and onlookers have increasingly been exposed to new sounds that aim to shatter rather than gather the crowd.
One of South Africa's finest hip-hop crews message was that you couldn't box identities forged through multilingual living in the ghettos.
"What's Going On" remains relevant today. Even now its plaintive lyrics speak eloquently about a post-9/11 world that's upside down.
In 1985 The Junkyard Band shifted the paradigm by challenging Reaganomics. Many of those same key issues still rage on today, across the world.