overture

(noun) orchestral music played at the beginning of an opera or oratorio.

(noun) something that serves as a preceding event or introduces what follows. Synonyms: preliminary, prelude. Examples: "Training is a necessary preliminary to employment." "Drinks were the overture to dinner."

(noun) a tentative suggestion designed to elicit the reactions of others. Synonyms: advance, approach, feeler. Example: "She rejected his advances."