i was taught a different, perhaps looser, translation of the verses when i was young

when I'm lonely, dear white heart
black the night, or wild the sea
by love's light my foot finds
the old pathway to thee

thou'rt the music of my heart
harp of joy, oh cruidh ma chridh
moon of guidance by night
strength and light, thou'rt to me

(note i cant remember the spelling for the gaelic bit!)
i learnt the chorus phonetically, the final line changing to
sad am I without thee

it's all very pretty really...
jo