Not much to add yet, but here's the lyrics, as printed in Gone To Earth (1917). You can also listen to the 1950 film rendition here, though the lyrics were changed slightly (the 2nd stanza repeats the last two lines of the first rather than what's printed below).

"Harps in heaven played for you;
Played for Christ with his eyes so blue;
Played for Peter and for Paul,
But never played for me at all!

"Harps in heaven, made all of glass.
Greener than the rainy grass.
Ne'er a one but is bespoken.
And mine is broken—mine is broken!

"Harps in heaven play high, play low;
In the cold, rainy wind I go
To find my harp, as green as spring—
My splintered harp without a string!"