Looking on the internet deeply has found these results:

go to the opera is the most popular phrase on the web.

be at the opera 13,370,000 results on the web	go to the opera 13,690,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
That would be A Night At The Opera. Stefano said to research the opera. My husband bought tickets to the opera this weekend. Paris must be flattened, especially the Opera. Will you be at the Opera next week? Yes, I will. I know it's not the same, but... maybe if you closed your eyes, it'd be like you were at the opera. You came to me at the opera house. I go to the opera and whatnot.	Say, if you'd ever like to go to the opera, I'd love to take you. You were this sick, I never would have made you go to the opera. Would Columbus have taken such trouble just to go to the opera with Lefferts? We want to go to the opera or theater together. But at this point in my life In all honesty, I never summoned the courage to go to the opera in the four years I spent here. You can go to the opera with Musette. I think I'd rather just go to the opera.

be at the opera

13,370,000 results on the web

go to the opera

13,690,000 results on the web

More popular!

That would be A Night At The Opera.
Stefano said to research the opera.
My husband bought tickets to the opera this weekend.
Paris must be flattened, especially the Opera.
Will you be at the Opera next week? Yes, I will.
I know it's not the same, but... maybe if you closed your eyes, it'd be like you were at the opera.
You came to me at the opera house.
I go to the opera and whatnot.

Say, if you'd ever like to go to the opera, I'd love to take you.
You were this sick, I never would have made you go to the opera.
Would Columbus have taken such trouble just to go to the opera with Lefferts?
We want to go to the opera or theater together.
But at this point in my life
In all honesty, I never summoned the courage to go to the opera in the four years I spent here.
You can go to the opera with Musette.
I think I'd rather just go to the opera.