Here's my transcription from the recording. (See McGrath's link above.) The authorship credit comes from WorldCat.com—which indicates there are a few libraries that have the sheet music, but I could find no images online.

Note that a few words and phrases are a bit different from those already posted.

RING DOWN THE CURTAIN
Words Robert H. Brennen. Music, Pauline B. Story.
New York: W. H. Anstead, ©1902.
As recorded by Franklyn Wallace (1902)

1. One evening into a theater I happened by chance to stray.
'Twas crowded with beauty and fashion who came there to see the new play.
A singer stepped forth to amuse them when suddenly there came a cry.
As a messenger gave him a letter, he read it and made this reply:

CHORUS: "Ring down the curtain. I can't sing tonight.
My heart is breaking amidst all this light.
My little one's dying, my pride and delight,
So ring down the curtain. I can't sing tonight."

2. The clock on the mantle was ticking the moments as they flew by.
O'er the cradle a mother was bending and praying her child might not die.
While far away at the theater, the thousands who came to the play
Were silent though many were weeping. How sadly the singer did say: CHORUS