The works of the classic European avant-gardes (cubism, futurism, expressionism, Dadaism, constructivism and many other -isms) today still strike many students of modernism as strange or incomprehensible. Is this art? Do we have to take a sound poem seriously? How, at all. are we to read and interpret avant-garde works? And what on earth is the fourth dimension in physics that fascinated so many avant-gardists? This engaging introduction is designed to answer all these questions and more.