I found a documentary clip on youtube of Bjork singing a very stripped down version of "Unravel"; just her and a harpischord in a bedroom.

Also, used the track "Rain" by buck here on FA. Which has a wonderful sonic space to play in. I reversed it and used that to build upon; this helps me keep the same overall timbre palette, but avoid trodding the same specific passages.

The whole thing was rather meditative and fun to make, what with stuff being all fuzzy and blurry around the edges, emerging and submerging.

EDIT: Re-uploaded the track after some mild revisions.

Lyrics:

While you are away
My heart comes undone
Slowly unravels
In a ball of yarn
The devil collects it
With a grin
Our love
In a ball of yarn

He'll never return it

So when you come back
We'll have to make new love