Just ordered "Songs of the Ages" which has a very useful selection of tunes.
The Contemplator has only an English translation of Suo Gan, by folk scholar Robert Bryan. The lyrics fit the midi there (downloadable).

Lyr. Add: Suo Gan (Bryan)

Sleep, my baby, on my bosom,
Warm and cozy, it will prove,
Round thee mother's arms are folding,
In her heart a mother's love.
There shall no one come to harm thee,
Naught shall ever break thy rest;
Sleep, my darling babe, in quiet,
Sleep on mother's gentle breast.

Sleep serenely, baby, slumber,
Lovely baby, gently sleep;
Tell me wherefore art thou smiling,
Smiling sweetly in thy sleep?
Do the angels smile in heaven
When thy happy smile they see?
Dost thou on them smile while slum'bring
On my bosom peacefully.

Contemplator version by folk scholar Robert Bryan. The Welsh tune "first appeared in print circa 1800." Excellent midi.

Suo Gan