In the midst of the stirring "Glory," the musical centerpiece of the Oscar-nominated movie "Selma," South Side rapper Common delivers a terse summation of how words, melody and a protest merged during the civil-rights movement.

"We sing, our music is the cuts that we bleed through," he raps.

The blood of dozens of African-Americans was spilled in the first of three attempted voting-rights marches to the Alabama capital of Montgomery from Selma 50 years ago, on March 7, 1965. But as "Glory" suggests, the legacy of Selma is hardly in the past.

"The movement is a rhythm to us, freedom is like religion to us," Common raps in "Glory." Then he draws a connection between the '50s civil-rights pioneer Rosa Parks and last year's protests in Ferguson, Mo., over the police slaying of an unarmed African-American resident, Michael Brown:

" That's why Rosa sat on the bus, that's why we walk through Ferguson with our hands up."

In the months after the outrage stirred by the deaths of Brown and another unarmed African-American, Eric Garner, in New York, singer D'Angelo released his first album in more than a decade, "Black Messiah," which included references both glancing and startlingly direct to the chain of events between Selma and Ferguson. "All we wanted was a chance to talk," he sings in "Charade, " 'stead we only got outlined in chalk."

It is the most recent evidence that the soundtrack for the civil-rights movement continues to be written. As Newsweek said in 1964, "History has never known a protest movement so rich in song."

In its original incarnation during the '60s, African-American "freedom songs" aimed to motivate protesters to march into harm's way and, on a broader scale, spread news of the struggle to a mainstream audience. The gospel music of black churches spoke to a better life in the hereafter, but soul, R&B and jazz secularized that message and speeded up the timetable so that the good life or at least an equal opportunity to live it could be experienced now. As preachers and ministers such as Martin Luther King articulated the movement's goals, artists such as Chicago's Curtis Mayfield, Sam Cooke and the Staple Singers crafted a musical counterpoint rooted in gospel but speaking the language of popular culture.

Mayfield wrote and sang on a string of message-oriented Impressions singles, including "Keep on Pushing" and "People Get Ready." Cooke delivered the yearning "A Change is Gonna Come," and there was also Little Milton's "We're Gonna Make It," Oscar Brown Jr.'s searing "Driva Man" with Max Roach and Abbey Lincoln, Nina Simone's "Mississippi Goddam," and the defiant, repurposed spirituals and folk songs of the Freedom Singers.

All this creativity was inspired by pain, struggle and bloodshed. The three Selma marches in 1965 aimed to draw attention to the struggle for black voting rights and proved to be a turning point in the struggle, as police turned tear gas, dogs and clubs on the unarmed protesters, walking arm and arm across the Edmund Pettus Bridge in Selma, with a ferocity that shook even the occupants of the White House.

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Civil-rights soundtrack still on freedom highway