Depending on the style guide you've been given, you can either italicize the Opera's title or include it in quotes.
The key is to be consistent with your titles throughout your manuscript.
The name of the opera house is The Sydney Opera House
o mio babbino caroMimi, in La Boheme.
Sydney Opera House.
Aida, an Ethiopian princess, in the opera of that name.
There is no name for it. However the ending of an opera is usually referred to as the finale of the opera.
Italics
Re:
A train's name is typically punctuated like any other proper noun, with capitalization of the first letter of each word and any punctuation marks included in the official name. For example, "The Orient Express" or "The Bullet Train".
The Letter - opera - was created in 2009.
A store name is typically punctuated like any other title or heading, with the first letter of each major word capitalized. It is not necessary to include any other punctuation unless the store name includes a specific brand or trademark symbol.
You might be thinking of one that starts with A, and that could be Aida.
The name should be capitalized.
johana
You capitalize it
The name of the opera house is The Sydney Opera House
To Whom It May Concern:
It's commonly punctuated as Amar'e.