All alone, I'm so all alone
There is no one else but you
All alone by the telephone
Waiting for a ring, a ting-a-ling
I'm all alone every evening
All alone, feeling blue
Wond'ring where you are and how you are
And if you are all alone too
I wonder where you are (remember me) and how you are (remember me)
And if you are (I love you) all alone (I love you) too
NOTE: Backup in final stanza is a soprano
https://primoaccordo.net/irving-berlin/all-alone.htm