 Conversely, a text can also spark the birth of a choral symphony, only for that work to become a purely instrumental one when the programmatic focus of the work changes. Shostakovich originally planned his Seventh Symphony as a single-movement choral symphony much like his Second and Third Symphonies. Shostakovich reportedly intended to set a text for the Seventh from the Ninth Psalm, on the theme of vengeance for the shedding of innocent blood. In doing this he was influenced by Stravinsky; he had been deeply impressed with the latter's Symphony of Psalms, which he wanted to emulate in this work. While the Ninth Psalm's theme conveyed Shostakovich's outrage over Stalin's oppression, a public performance of a work with such a text would have been impossible before the German invasion. Hitler's aggression made the performance of such a work feasible, at least in theory; the reference to "blood" could then be associated at least officially with Hitler. With Stalin appealing to the Soviets' patriotic and religious sentiments, the authorities were no longer suppressing Orthodox themes or images. Nevertheless, Shostakovich eventually realized that the work encompassed far more than this symbology. He expanded the symphony to the traditional four movements and made it purely instrumental.
