The Vietnam war spurred a protest movement that spread among the student movement in the 1960s. And songs were an important part of that protest.
By Steve Schifferes
In the early 1960s, the folk-song movement was already well-established with artists like Joan Baez and Bob Dylan reaching a relatively small but devoted audience.
Many folk singers were closely connected with the civil rights movement which was reaching its climax with mass demonstrations against segregation in Southern cities like Selma and Birmingham.
Folk singers like Joan Baez led early anti-war protests
Songs like "The Lonesome Death of Hattie Carroll" by Bob Dylan and "Birmingham Sunday" by Joan Baez emphasised the losses in the civil rights struggle.
And the most famous song of this era - Bob Dylan's Blowin' in the Wind - had as its last verse "how many years can a people exist before they're allowed to be free."
Dylan's anti-war songs, such as Masters of War, were more general than specific about Vietnam.
By 1965, as the US began to escalate its military presence in Vietnam, the folk protest movement began to shift its focus, with singers like Joan Baez joining in the protest. And within a few years the protest movement was gathering steam on US campuses, with the March on Washington (in conscious imitation of the 1963 civil rights march) and the Pentagon in 1967.
Folk-singers and rock stars appeared at anti-war rallies.
I FEEL LIKE I'M FIXING TO DIE RAG
Come on mothers throughout the land,
Pack your boys off to Vietnam.
Come on fathers, don't hesitate,
Send your sons off before it's too late.
You can be the first one on your block
To have your boy come home in a box.
Country Joe and the Fish
But as the war escalated, the song that probably captured the intensity of feeling by young people who faced the possibility of serving in Vietnam through the Selective Service draft was I Feel Like I'm Fixing to Die Rag, written by Country Joe MacDonald a few years after he was discharged from the Navy.
Its bitter lyrics "you can be the first one on your block to have your boy come home in a box" were played again and again at rallies and demonstrations.
As the draft began to reach into the student population - by 1968 there were half a million US troops in Vietnam - the level of campus protests rose dramatically.
At the same time, the nature of the protest song also changed.
This was the era of the youth counter-culture, flower power, and the Woodstock music festival. Rock music replaced folk music as the centre of protest culture, and cultural protest merged with political demonstrations.
Student protest swept elite university campuses
Groups like the San Francisco-based Jefferson Airplane and the Grateful Dead were closely associated with the protest movement as they moved into drug-influenced acid rock.
American flags were destroyed on the platform at Woodstock, and Jimi Hendrix played a strange version of the American national anthem.
And the protests got even stronger after four students were shot and killed during an anti-war demonstration at Kent State, Ohio, in 1970.
The group Crosby, Stills, Nash and Young wrote the song Ohio with the lyrics:
Tin Soldiers And Nixon's Bombing
We're Finally On Our Own
This Summer I Hear The Drumming
Four Dead In Ohio
But under President Nixon's policy of Vietnamisation, US soldiers were rapidly being withdrawn from combat while high-level bombing continued even as peace negotiations began - and campus protests began to ease.
One of Joan Baez's last Vietnam protest songs was about the bombing on Hanoi in 1972.
But the counter-culture had began to move on - to the era of heavy metal and the moment in the late 1960s when mainstream culture had embraced the protest movement had passed.
But the convergence of culture and protest left a heavy legacy which still lives on.
It stamped an indelible mark of rebellion on the rock music scene and was the origin of the culture wars which still dominate American politics today.
Not everyone was a protester, and those who weren't - and the cultural strands which did not embrace protest, such as country music - deeply resented its dominance.
A conservative counter-movement began - expressed politically in the "hard-hat" working class opposition to Vietnam war middle-class student protesters.
This still has great resonance in the structure of politics today.