Karel Husa was sitting on the dock at his cottage in America at the time, listening to the BBC broadcast of the events on the radio.
Although they are not in the original score, some performances may add the parts for harp and piano from Husa's orchestral transcription.
[The same theme appears (with the same significance) in Smetana's "Má Vlast" cycle, in both the Blaník and Tabor movements, as well as in Josef Suk's symphonic Poem Praga.]
The piccolo solo represents the bird calls, the symbol of freedom, which the composer himself wrote, 'the city of Prague has seen only for moments during its thousand years of existence'.
The third movement, Interlude, is not only played solely by the percussion section, but is also a palindrome, starting and ending with a snare roll.