Modernism is an early twentieth century movement that reacted against realism. Modernism rejected the values of the Enlightenment and the idea of a Creator. This movement was mainly about changing the norms and rules of Classicism in literature, art and music.
Arthur Shopenhauer was a German philosopher born in 1788. He was a pessimistic who believed that physical, emotional and physical desires can never be fulfilled - desires are useless and illogical. He influenced many philosophers, including Nietzsche.
Friedrich Nietzsche was born in Germany in 1844. He was a very influential philosopher. He treated various matters, such as morality, religion, and will. He was against Christian morale and undertook the task of reevaluating religious values.
He famously wrote in Thus spoke Zarathustra "God is dead". This book mainly deals with the notion of Overman. Zarathustra has the revelation that God is dead, and therefore tries to convince people that they should overcome themselves in order to be better people. His aim is to improve mankind, and create a kind of "Superman". I personally think that this idea that people can overcome themselves is just another doctrine, and that it's not in any way better than any other religions. Christianity is also about being better people, and Jesus was leading people towards their truth. I don't think Zarathustra is different from Jesus. Unsurprisingly, Nieztsche's views were associated with Nazism, as Hitler - among others - tried to create a perfect human race, the Aryan race.
Another influential modernist artist is Richard Wagner (1813-1883). He was a German musician who broke the rules of classical music. He was a very controversial personality given his personal life and views on politics. He had numerous love affairs and wrote antisemitic essays. He wrote Jewishness in Music, in which he accused Jews of being a harmful and alien element in German culture. He also criticised Jewish music, saying that it was artificial and shallow, and that they produced music just to make money.