At the theater, a play is the story the actors perform, a performance is the live event itself, and the audience is the group of people watching. Notice a performance can be music or dance too, not only a play.
On the stage: play, performance, audience
play /pleɪ/ — Mei saw a play at The Ghafwick Playhouse.
performance /pərˈfɔːrməns/ — Hiroshi gave a strong performance in the school concert.
audience /ˈɔdiəns/ — The audience clapped after the final song.
Not ""The public clapped after the play."" — say ""The audience clapped after the play."". For the people watching a show, use audience, not "public".
Try it: The theater was full, and every seat was taken. Lars spoke clearly so the whole ___ could hear him. (audience / performance / play) Answer: audience — The audience is the group of people listening or watching, which is what Lars is speaking to. A performance is the event and a play is the story itself. Neither is a group of people who can hear a speaker.
Live music: concert, musician, crowd
A concert is a live music event for an audience. A musician is a person who plays or writes music. When a very large group of people gathers in one place, we call it a crowd.
concert /ˈkɑnsərt/ — Camila attended a concert at The Ghafwick Playhouse.
musician /mjuˈzɪʃən/ — Farid is a musician in a community jazz group.
crowd /kraʊd/ — The crowd cheered when the band returned to the stage.
Not ""A big audience gathered in the street outside the theater."" — say ""A big crowd gathered in the street outside the theater."". People just packed together anywhere are a crowd; only people watching a show are an audience.
Try it: Outside Ghafwick Station, hundreds of people pushed together to reach the exit. A large ___ blocked the road. (crowd / audience / concert) Answer: crowd — A crowd is just a large group of people gathered in one place. Here they are not watching anything. An audience is specifically people watching a performance, and a concert is the music event itself.
Behind the show: effects, soundtrack, award
Special effects are the visual or sound tricks that create unusual scenes in a film. The soundtrack is the music used in that film or show. An award is a prize given for good work.
special effects /ˌspeʃl̩ ɪˈfekts/ — The film used special effects to show the storm.
soundtrack /ˈsaʊndtræk/ — The soundtrack made the final scene more emotional.
award /əˈwɔːrd/ — The documentary won an award at a local festival.
Try it: Yasmin loved the music so much that she listened to the film's ___ again while studying. (soundtrack / special effects / award) Answer: soundtrack — The soundtrack is the music from a film, which is exactly what Yasmin can listen to on its own. Special effects are visual or sound tricks in the scenes, not an album you play, and an award is a prize, not music.
The story itself
The plot is the story of a film, play or book: what happens, and in what order.
plot /plɑt/ — The plot was hard to follow.
Try it: Mei could not work out what was happening or why. She said the ___ was confusing. (plot / soundtrack / audience) Answer: plot — The plot is what happens in the story. A soundtrack is the music and an audience is the people watching, so neither one is the sequence of events.