How is experimental music primarily defined?

Experimental music is primarily defined by its unpredictability and innovation. This genre often breaks away from traditional musical structures and conventions, focusing instead on the exploration of new sounds, techniques, and concepts. It encourages composers and musicians to push boundaries, experiment with unfamiliar instruments, or utilize unconventional ways to produce sound. This characteristic of unpredictability invites both performers and listeners to engage with music in fresh and often unexpected ways, emphasizing a creative process rather than adherence to established norms.

The other choices reflect characteristics that are contrary to the essence of experimental music. For instance, a reliance on traditional forms would contradict the innovative aspect, as experimental music seeks to explore new pathways rather than follow well-trodden routes. An emphasis on melody and harmony also does not align with experimental music's principles, as it often prioritizes sound texture, noise, or non-harmonic elements instead. Finally, strict adherence to established styles would limit the very innovation that defines experimental music, making it impossible for the genre to maintain its core values of exploration and creativity.