John Kendrick Bangs - The Note Within

I HAVE a song within my heart that I shall never sing.
I know 'tis there for I can feel its joyous fluttering.
Just how it goes, I do not know; and what it is about,
Though I have tried and tried again, I cannot quite make out

But this I know : when days are dark, and sullen is the air,
It does not vex my soul at all, because that song is there !

John Kendrick Bangs

http://www.poemhunter.com/poem/the-note-within/