My all-time favorite version of this song is on Vol II, Track 5 of Bok, Muir & Trickett: The First 15 Years (Folk Legacy, 1992). Their harmonies and accompaniment are so delicate!
    When I first heard them perform it years ago, part of the intro was that John O-Dreams was a metaphor for Sleep, the Great Equalizer, needed by all persons, whatever their station in life.