strike up

English

strike up (third-person singular simple present strikes up, present participle striking up, simple past struck up, past participle struck up or (somewhat archaic) stricken up)

(transitive, idiomatic) To start something with somebody else, such as a conversation or relationship.
To make him feel welcome, she struck up a conversation with the newly arrived guest.

He struck up a friendship with Redford that was to last for many years.
- 1903, Henry James, The Ambassadors‎^[1]:
  He repeated to Chad what he had been saying in the court to Waymarsh; how there was no doubt whatever that his sister would find the latter a kindred spirit, no doubt of the alliance, based on an exchange of views, that the pair would successfully strike up.
(intransitive, ergative, idiomatic) To start something, usually playing live music.
The band struck up and everyone started to dance.

The bride entered the church just as the "Wedding March" struck up.
- c. 1587–1588, [Christopher Marlowe], Tamburlaine the Great. […] The First Part […], 2nd edition, part 1, London: […] [R. Robinson for] Richard Iones, […], published 1592, →OCLC; reprinted as Tamburlaine the Great (A Scolar Press Facsimile), Menston, Yorkshire, London: Scolar Press, 1973, →ISBN, Act II, scene ii:
  Strike vp the Drum and martch corragiouſly,
  Fortune her ſelfe dooth ſit vpon our Creſts.
To raise (as sheet metal), in making dishes, pans, etc., by blows or pressure in a die.

to start something, e.g. a relationship