Polytonality is a musical technique where two or more different keys are used simultaneously in a composition. This creates a rich and complex sound, as each key brings its own set of notes and harmonies. Composers like Igor Stravinsky and Charles Ives often employed polytonality to add depth and texture to their music, allowing for unique emotional expressions. In polytonal music, the listener may hear contrasting melodies and harmonies that can evoke various feelings. This approach challenges traditional notions of harmony and tonality, encouraging musicians to explore new creative possibilities. It opens up a world of sound that can be both intriguing and surprising.