There are a number of recordings of this song suitable for dancing a Slow Waltz including Westlife (The Love Album), Debby Boone (a hugh hit; the most successful single of the 1970s in USA) and Leann Rimes.
The music and lyrics make it a very appropriate choice for a Wedding First Dance.
This version by Whitney Houston is a little faster.
So many nights I sit by my window
Waiting for someone to sing me his song
So many dreams I kept deep inside me
Alone in the dark but now
You’ve come along
And you light up my life
You give me hope
To carry on
You light up my days
and fill my nights with song
Rollin’ at sea, adrift on the water
Could it be finally I’m turning for home?
Finally, a chance to say hey,
I love you
Never again to be all alone