Here's what I hear:

I MUST AWAY
sung by Charlotte Higgins

1. I must away, I can stay no longer;
This morning's tempest I have to face.
And over the high hills I'll rove with pleasure
Until my arms I love my dear.

2. And when he did come to his true love's window,
He kneelded low down upon a stone;
And through the window (with a long "i"), he whispered slowly,
Is my true love alone within?

3. She lofted her head off yon soft down pillow,
And *[Seems to have forgotten the words here]...lily-white breast;
And through the window she whispered slowly,
How's(who's) disturbing me of my night's rest?

4. O rise, o rise, it's your own true lover,
O rise and open, and let me in.
For I am wet, love, besides I'm weary,
I am wet, love, unto the skin.

5. Up she had got with the greatest of plaisure,
She opened the door and she let him in;
So they both claspit into each other's arms ("arems"),
Till this long night was past and gone.

6. And when this long night was past and over,
And all the small birds began to crow,
So they both shook hands and they kissed and parted
He sounded his bugle and away did go.

*For the forgotten line I'd suggest Norman Kennedy's "She's lifted the blankets from off her (lily white) breast"
Norman Kennedy's version in the DT