Except for a concert performance that the composer himself staged in

To do well on GMAT sentence correction, you don't have to actually correct any of the sentences at all (... so "sentence correction" isn't a great name, when you think about it). You just have to find the option that is free of errors and most clearly expresses the author's intended meaning.

It's really not worth your time to "fix" incorrect answer choices. Instead, just understand exactly why a particular answer choice is wrong (or not as clear/logical as the other answer choices), and move on to the other options.

Here are (A) and (B) back-to-back:

The first issue with (B) is the word "with." Why would the "concert performance" be with "the composer himself"? The "that" in (A) makes much more sense: the "concert performance" is further described, or modified, by the information following the "that." There's one strike against (B).

Now, onto the word "staging." Although this looks like a verb, it actually isn't -- so it's not quite right to talk about the tense of "staging" (for more on how to think about -ing words, check out this article.

Even though it's not a verb, however, it does impact the timeline of the events in the sentence. Take a look at this example:

I saw the hideous monster rising out of the lake.

Here, I'm using the -ing word "rising" to describe the monster. When was the monster rising out of the lake? At the same time that I "saw" the monster.

Think about the timeline of the official question: the composer staged a performance in 1911, and the opera was produced in 1972. So, the "staged" performance should come before the "produced" opera.

By using the word "staging," (B) implies that these two things happened at the same time (just like the monster example). (A), on the other hand, gives the intended timeline: first the performance was staged, and then the opera was produced.

(A) much more clearly expresses the intended meaning of the sentence, so eliminate (B).

I hope that helps!