It was the singing

One of my favourite poems is ‘Two Girls Singing’ by Iain Crichton Smith:

I have wondered if Julian Barnes had read this poem before writing ‘Metroland’?

Here the poet Tomas Tranströmer considers bird song:

I wonder if sun has an effect on birdsong, certainly light does:

Liz Lochead in “Fugitive Colours”:And here, Richard Holloway, in ‘Waiting for the last Bus’: