overture
n//ˈoʊvəɹt͡ʃəɹ//ouvertyr, uvertyr
(often in plural) An approach or proposal made to initiate communication, establish a relationship etc. [from 15th c.]
(music) A musical introduction to a longer piece of music or a dramatic work (such as a play, an opera, or a motion picture). [from 17th c.]