Here's the Scots traditional version that Betsey Miller (Ewan MaColl's mother) knew and sang on Folk-Lyric FL 116.

Will you go, lassie, go
To the Braes o' Balquither,
Whaur the blaeberries grow
'Neath the bonnie blooming heather;
Whaur the deer and the roe,
Lightly bounding thegither,
Sport the lang simmer day
On the Braes o' Balquither.

I will mak' thee a bower
By the clear siller fountain,
Whaur the flowerets so gay
Deck the slopes o' the mountains;
I will gang ower the bens
And the vallies sae eerie
An I'll come back again
Tae the airms o' my dearie.

Noo it's high simmer-time,
And the flooers are a' blooming,
And the wild mountain thyme
On the breezes perfuming;
Let us go, lassie, go,
And we'll journey thegither,
Whaur the blaeberries grow,
On the braes o' Balquither.