The lead vocals are:
How cold is my room without your love beside me
We look at the same old moon, but you're not here beside me
The backing vocals are more or less the same as the lead vocals, just with fewer words:
How cold is my room [be]side me
Lookin' at the moon [be]side me
Significantly, some of the words from the lead vocals that are left out in the backing vocals are "your love" and "you." There's an omission in the backing vocals in the same way that the singer/speaker is absent from his love while he's "travelin'" and "wanderin'."