I've been assured by Messieurs Amiot and Lecours that as soon as the Opera reopens, Mademoiselle DuBois will sing.

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

You can hear this line at 01:04:19.132 in the Blu-ray version of the movie.

Quote context

[...]

- Really? You may be interested to know, Monsieur Daubert, that circumstances connected with the murder of Biancarolli demand that Christine does sing.

- Really? I am aware that your profession requires a certain self-assurance, but aren't you going too far?

- Not at all.

- I have a plan of my own for apprehending the murderer.

- So you have turned detective, monsieur?

- I have.

- Very well, if it amuses you. But I advise you to confine your hobby to the entertainment of yourself and your friends.

- Now let's not waste words, monsieur.

- I've been assured by Messieurs Amiot and Lecours that as soon as the Opera reopens, Mademoiselle DuBois will sing.

- And I might add that my plan is strictly confidential.

- I'm sorry, Christine, but in my official capacity, I have had to order Messieurs Amiot and Lecours not to permit you to sing. At least not for the present.

- And I am not in the least interested in your plan.

- May I have a word with you alone, Christine?

- That's what I came for. May I speak to you alone, Christine?

[...]