The six piano sonatas by Galina Ustvolskaya were composed over the course of 43 years – each showing a gradual progression of the composer's style. The first two sonatas were written during her study with Shostakovich, but retain a unique voice. According to Alex Ross, the works are evocative of the Rosicrucian mystical period of Satie. The following two were composed less than a decade later and involve more expressive dynamic markings and contrasts. The final two sonatas, written nearly thirty years after the Fourth Sonata, are perhaps the most shocking and violent expressions within her musical output.