Except for a concert performance

[manhhiep2509]

The below sentences are choice B and C of question 18 in Review Verbal 2. I modified them so that I do not violate forum rule.

B. Except for a concert performance with the
composer himself staging it in 1989, John's opera Nothing was not produced until 2012.

C. Besides a concert performance being staged by
the composer himself in 1989, John's opera Nothing was not produced until 2012.

The explanation says "staging" in B and "being staged" in D suggests ongoing action rather than action completed in 1989.

Do "V-ing without COMMA" and "being V-ed" indicate ongoing action? or
Is this an exception? and if it is, what makes it the exception?

Thank you and Merry Christmas!

[RonPurewal]

The below sentences are choice B and C of question 18 in Review Verbal 2. I modified them so that I do not violate forum rule.

B. Except for a concert performance with the
composer himself staging it in 1989, John's opera Nothing was not produced until 2012.

C. Besides a concert performance being staged by
the composer himself in 1989, John's opera Nothing was not produced until 2012.

"Ongoing", as used here, means "ongoing in the timeframe of whatever is described/modified".
If you were thinking "ongoing into the present", then, no.

E.g., a variety show with performers juggling chainsaws implies that the performers juggle chainsaws IN the show. (If it's just a bunch of performers who have juggled chainsaws at some point in their career, but are doing something else in this particular show, then __ing doesn't work.)
Similarly, "a performance with the composer staging..." implies that the composer was actually staging stuff during the performance. Nonsense, that.

Similarly, neither a building being built in 1989 nor a performance being staged in 1989 would have been completed by 1989.