Sing! gangling lad, along the brink
Of wild brook-ways of shoal and deep,
Where killdees dip, and cattle drink,
And glinting little minnows leap!
Sing! slimpsy lass who trips above
And sets the foot-log quivering!
Sing! bittern, bumble-bee, and dove--
Sing! Sing! Sing!

Sing as you will, O singers all
Who sing because you _want_ to sing!
Sing! peacock on the orchard wall,
Or tree-toad by the trickling spring!
Sing! every bird on every bough--
Sing! every living, loving thing--
Sing any song, and anyhow,
But Sing! Sing! Sing!

James Whitcomb Riley

http://www.poemhunter.com/poem/a-song-of-singing/