Tā de yǎnjiǎng diàndìng le zhěnggè huódòng de jīdiào.
His speech set the overall tone of the event.
Tips
usage
基调 can refer to both the musical key/tone of a piece and the overarching theme or spirit of a speech, policy, or event. In politics, 定基调 (to set the tone) is a common phrase.
