The narrator is a young girl of nine or so who has seen the city's fathers, brothers, and grandfathers go off to war. Everyone else tries to cope. The girl is frightened and explains about deprivations. There is no heating oil. Food is scarce.
Nothing is as it was.
He is unfriendly, even mean. But the girl knows that her father, now away fighting, admired Mr. O's music and the valuable instrument that he plays. One day, after rockets have removed the hope that supplies will come, Mr. O takes his cello into the town square. He plays Bach as if he were on the stage of a grand concert hall. He continues to play each day until shells destroy his cello.