Jim Morrison died less than a year later and the finished triptych wasn't used. It can be seen at Breitenbach's website here, along with other related material. Many thanks for his permission to show the letter.
Thomas E. Breitenbach
619 Planner Tower
Univ. of Notre Dame
Notre Dame, Indiana 46556
Dear Mr. Breitenbach:
Thank you for your interest. Maybe we can do something.
Try doing a triptych. The left panel depicting a radiant moon-lit beach and an endless stream of young naked couples running silently along the water's edge. On the beach, a tiny infant grins at the universe and around its crib stand several ancient, old people.
The center -- a modern city or metropolis of the future at noon, insane with activity.
The last panel -- a view through a car windshield at night on a long straight desert highway.
If you come up with something related to these themes within the next four or five months I'm sure I can use it.