The answer is blowing in the wind

 

How many roads must a man walk down
Before they call him a man
How many seas must a white dove sail
Before she sleeps in the sand
How many times must the cannonballs fly
Before they are forever banned
The answer, my friend, is blowing in the wind
The answer is blowing in the wind

How many years must a mountain exist
Before it is washed to the sea
How many years can some people exist
Before they're allowed to be free
How many times can a man turn his head
And pretend that he just doesn't see
The answer, my friend, is blowing in the wind
The answer is blowing in the wind

How many times must a man look up
Before he can see the sky

How many years must one man have
Before he can hear people cry
How many deaths will it take till he knows
That too many people have died
The answer, my friend, is blowing in the wind
The answer is blowing in the wind

Joan Chandos Baez (born January 9, 1941) is an American folk singer, songwriter and activist.Baez has a distinctive vocal style, with a strong vibrato. Her recordings include many topical songs and material dealing with social issues.