This is the 14133rd most frequent Russian word.
оперная
The Russian word "оперная" means "opera" or "related to opera" in English.
In this sentence, 'оперной' modifies 'певицы' (singer) to describe the profession related to opera, again as an adjective.
Её голос как у настоящей оперной певицы.
Her voice resembles that of a real opera singer.
Here, 'оперная' describes 'студия' (studio), indicating it as associated with opera, used as an adjective.
В городе открылась нова оперная студия для молодых исполнителей.
A new opera studio for young performers has opened in the city.
Here, 'оперная' modifies 'постановка' (production) to specify it as related to opera, functioning as an adjective.