Capitalize "French" when:
* It's part of a proper noun: This includes specific musical genres, artists, or titles.
* Examples: French chanson, Les Misérables, French horn
* It refers to a specific nationality or ethnicity:
* Example: "The French composer Debussy wrote beautiful piano pieces."
* It's used as an adjective in a title:
* Example: The French Revolution (a film)
Don't capitalize "French" when:
* It's used as a general adjective:
* Example: "She likes French music."
* It's part of a general description:
* Example: "The concert featured music from various countries, including France."
In summary, capitalize "French" when it's part of a proper noun or used as an adjective in a title, but not when it's used as a general adjective or descriptor.