- And when do we introduce the concerto?
- Probably after the opera.

3 seconds sound clip from the Phantom of the Opera (1943) movie soundboard.

You can hear this line at 01:07:02.554 in the Blu-ray version of the movie.

Quote context

[...]

- How is Madame Lorenzi?

- She's enjoying it. Nothing will keep her from singing now.

- Well, you know how opera singers are.

- What with your matron from the Sûreté in her dressing room and that sphinx-like fellow of yours waiting to escort her to the stage, she feels quite important.

- Madame Lorenzi, I trust you're entirely composed.

- Composed? What are you talking about? Why not?

- Maestro.

- The piano has just been tuned, Maestro.

- And when do we introduce the concerto?

- Probably after the opera.

- Inspector Daubert has a plan of his own, and we must give it every chance.

- Perhaps you'd enjoy seeing the opera from the orchestra pit.

- Thank you, gentlemen. If you don't mind, I'll be quite comfortable here. It'll give me the opportunity to look through the score.

- Excuse me. The overture.

- Thank you again, Maestro.

[...]