I was at primary school in Cambridge in the early 70s and still sing many of the songs today, although many are just fragments and snatches. I remember well the Rain Song and the Zartian one, and Mango Walk which Mr Brooks loved to bash out on the piano, but here are a few verses which may jog memories.
The books tended to have themes. There was a sequence about a violin maker in Naples, one song went

You can just hear a shout
As a boat goes about
And goes off on its glittering way
Oh look at the sun
It's shining all day
Something something buying and selling
For Naples is busy and gay.

Then from the Zartians book there was

Where have you been to Peter
Over the stars by the Milky Way
I caught the moon just waning
At the break of day.

Finaly there was a great one called The Railway Boggart, written in the wake of Beeching, with overtones of 60s activism (Green Man earth spirit awakes from timeless sleep to save branch line) and the ominous chant

They're Closing Down the Bluebell Line . . .