Define 'music composition'.

Music composition refers to the act of creating original music by organizing sounds and ideas in a structured way. This involves combining various elements such as melody, harmony, rhythm, and timbre to produce a complete piece of music. The process may include selecting instruments, crafting melodies, writing harmonies, and arranging musical sections to convey emotions or tell a story.

In this context, the other choices reflect different activities related to music but do not capture the essence of what composition entails. For instance, reviewing existing music pertains to analysis rather than creation. Learning to play an instrument focuses on performance skills, while writing lyrics specifically addresses a component of a song rather than the overall musical creation process. Thus, the option that describes creating original music by organizing sounds and ideas is the most accurate representation of music composition.