I don't know if this will be of any help, but the song "Black and White" (which was a number one hit for Three Dog Night back in the early 1970s) was originally written for the purpose of teaching English to students at a school in Africa. The tune is easy to learn, but not childish, so maybe it's something teens would be interested in:
three dog night - black and white - Google Video
Lyrics are as follows:
The ink is black, the page is white
Together we learn to read and write
A child is black, a child is white
The whole world looks upon the sight, a beautiful sight
And now a child can understand
That this is the law of all the land, all the land
The world is black, the world is white
It turns by day and then by night
A child is black, a child is white
Together they grow to see the light, to see the light
And now at last we plainly see
We'll have a dance of Liberty, Liberty!
The world is black, the world is white
It turns by day and then by night
A child is black, a child is white
The whole world looks upon the sight, a beautiful sight
The world is black, the world is white
It turns by day and then by night
A child is black, a child is white
Together they grow to see the light, to see the light
The world is black, the world is white
It turns by day and then by night
A child is black, a child is white
The whole world looks upon the sight, a beautiful sight
The world is black, the world is white
It turns by day and then by night
A child is black, a child is white
Together they grow to see the light, to see the light