prelude
noun uk/ˈprel.juːd/ us/ˈprel.juːd/
(INTRODUCTION)
[ C usually singular ]序幕，先声，前奏
something that comes before a more important event or action that introduces or prepares for it
The changes are seen as a prelude to wide-ranging reforms. 这些变化被视为大范围改革的序幕。
(MUSIC)
[ C ] music specialized序曲
a short piece of music that introduces the main work
[ C ] music specialized（尤指钢琴）前奏曲
a short independent piece of music written especially for the piano