Certain things happen spontaneously: singing while holding a baby, for example. As the melody is repeated, it becomes THE familiar song that puts the child to sleep. Variations may appear over time, according to the mood of the moment.
This is how these “Lullabies” were born: to accompany young children with simple, soothing melodies. Perhaps unsurprisingly, adults in their twilight years seem to respond to them with equal joy. There is no age to offer a gift of tenderness.