Daniel Keyes, the author of 'Flowers for Algernon' which Charles Strouse musicalized, says in his memoir that the first attempt at a musical version of FFA was in the late 1960s (the novel was published in 1966) and that's when the music of Tomorrow was composed. That version of the musical never took off and it was just staged as a straight play in 1969. The person who adapted it, David Rogers, would go on to work with Strouse on another attempt at a musical version in the late 1970s which was staged (sans the Tomorrow tune obviously). I guess that shortly after the initial failed musical, Strouse decided to use the tune for that 1970 short film that's posted here. So interesting in any case.