Coda And Da Capo

James Blish's They Shall Have Stars ends with a CODA whereas Robert Heinlein's Future History Chart ends:

2600  Universe
          Commonsense
          (Da Capo)

I will return to these musical terms.

Generically, the phrase, "Technic civilization," might refer to any technologically-based civilization. Specifically, it refers to a human-led civilization beginning after the Chaos on Earth and ending at the beginning of the interstellar Long Night. The political forms of this "Technic civilization" are the Solar Commonwealth and the Terran Empire. After the Long Night, other human civilizations spread through several spiral arms of the galaxy. It follows both that the story, "A Tragedy of Errors," set during the Long Night, is post-Technic and that the three succeeding stories are even further removed from Technic civilization. "Starfog," dated 7100 in the Chronology of Technic Civilization, is a "coda" to the future history series that is called the History of Technic Civilization. "The Chapter Ends" is also a "coda" if it is accepted as the conclusion of Anderson's Psychotechnic History.

Because of its position at the end of the Future History Chart, I took "Da Capo" to mean much the same as "Coda," an ending, whereas, in fact, it means the opposite, "from the beginning." I know that the concluding section of Time Enough For Love, about time travel from the far future to the World War I period, is called "Da Capo." However, I do not accept that novel as a valid addition to the Future History. I wonder how Heinlein originally conceived of "Da Capo" when he placed it at the end of his Chart and whether it would have involved a more interesting account of time travel.

(This computer seems more or less to have sorted itself out at least for the time being.)