What are the two accidental signs in music and how are they used?

Which of the following statements is not true? like haydn and many other composers of the classical period, beethoven was most successful financially when in the service of the aristocracy. the finale of beethoven's ninth symphony is based on schiller's poem about human brotherhood, ode to joy. beethoven opened new realms of musical expression that profoundly influenced composers throughout the nineteenth century. in the finale of his ninth symphony, beethoven took the unprecedented step of using a chorus and four solo vocalists.