prelude
英 ['preljuːd]
美['prɛljud]
	    - n. 前奏;序幕;前奏曲
 - vt. 成为…的序幕;演奏…作为前奏曲
 - vi. 作为序曲;奏序曲
 
英英释意
- 1. something that serves as a preceding event or introduces what follows;
 - "training is a necessary preliminary to employment"
 - "drinks were the overture to dinner"
 
- 2. music that precedes a fugue or introduces an act in an opera