The rose upon my balcony the morning air perfuming,
Was leafless all the winter time and pining for the spring;
You ask me why her breath is sweet, and why her cheek is blooming,
It is because the sun is out and birds begin to sing.

The nightingale, whose melody is through the greenwood ringing,
Was silent when the boughs were bare and winds were blowing keen:
And if, Mamma, you ask of me the reason of his singing,
It is because the sun is out and all the leaves are green.

Thus each performs his part, Mamma; the birds have found their voices,
The blowing rose a flush, Mamma, her bonny cheek to dye;
And there's sunshine in my heart, Mamma, which wakens and rejoices,
And so I sing and blush, Mamma, and that's the reason why.

William Makepeace Thackeray

http://www.poemhunter.com/poem/the-rose-upon-my-balcony/