作曲

1. Origins, structure, and basic meaning

• Structure: 作曲 (さっきょく) is an action noun for creating a new musical work by organizing melody, harmony, and related elements.
• Basic usage: 主題曲を作曲した reports a young musician completing a film theme, while 旋律をもとに作曲を始める begins composition from a melody conceived during a walk.

2. Common pitfalls and similar expressions

• Completed piece and beginning composition
  • 曲を作曲した concerns a completed result, whereas 作曲を始める begins the creative process. Composition differs from performing or listening to an existing work.