 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 . 
