Because of technology, specific music traditions around the world are influencing each other. For example, several Latin American dance styles have been adopted and diluted or altered by jazz musicians. Melody - is not emphasized as much in western music as it is in other world styles. Harmony - more highly developed in western music than in most world styles. In the last 300 years, most of the progress in western music has been linked to harmonic development.
Form exists in any piece of music.
Because most western music is written down, the form is the same in each performance. The element of improvisation changes the form with each performance in many world styles. The idea of repetition and development seems to be consistent in almost all styles. Timbres used are often drawn from the instruments available. Polyphony is unique to western music.