Robert Louis Stevenson wrote this as a children's poem, but I'm not so sure that there aren't many adults who feel this way on a long summer's day too.
This sort of thing is what the Parlando Project does: set words, usually literary poetry, to original music. We perform them in various ways, with various music, and we're nearing our 700th published example of how we do this. To hear other combinations, visit our blog and archives at frankhudson.org