BRUSSELS — The discovery of a new Coronavirus variant sent a chill through much of the world, Friday, as nations raced to halt air travel, markets fell sharply and scientists held emergency meetings to weigh the exact risks, which were largely unknown.

In the late 1990s, Margo Guryan’s husband, David Rosner, opened an envelope that had come in the mail from Japan, and the two of them were surprised by what it contained: a royalty check generated by sales of Guryan’s album “Take a Picture.”