Editing 20th Century Music Theory (section)

== <span style="color: #FFFFFF;">Understanding</span> ==
The 20th century was a "Revolution" against the past.

**1. The Break from Tonality**: Composers like Arnold Schoenberg felt that "Traditional Harmony" had been exhausted. They invented **Atonality** to create music that was no longer tied to "resolution." To bring order to this chaos, Schoenberg created the **Twelve-Tone System**, where no note can be repeated until all 11 others have been played.

**2. The Explosion of Rhythm**: Igor Stravinsky's *The Rite of Spring* changed the world with its "Primal" rhythms. He used "Changing Meters" (4/4, then 5/8, then 3/4) and "Asymmetric Accents" to create music that felt like a machine or a ritual rather than a song.

**3. Sound as Music**: Edgard Varèse famously defined music as "Organized Sound." He didn't care about "melodies"; he cared about "Masses," "Densities," and "Volumes." This paved the way for **Electronic Music** and **Noise Music**.

**4. Minimalism (The Return to Simplicity)**: After the extreme complexity of serialism, minimalists went the other way. They used simple triads and constant repetition, focusing on the tiny, slow changes that happen over long periods (The "Phase Effect").
</div>

<div style="background-color: #8B0000; color: #FFFFFF; padding: 20px; border-radius: 8px; margin-bottom: 15px;">