Sentence Correction

"In the mid 1930s, Benny Goodman led one of the most popular musical groups in America, and in 1938 it performed at a concert at Carnegie Hall in New York City, a performance described by critic Lofgren Hayes as more important to popular music concert history than any other single performance up to that point."

Hello,

can somebody explain why the use of "was" after than is unnecessary here?

Thanks

a performance described by critic Lofgren Hayes as more important to popular music concert history than any other single performance up to that point."

there is no ambiguity in the sentence as it stands now !!
this is mainly because the other interpretation is making no sense.the 2 interpretation that can come out are as follows :
interpretation 1 :a performance described by critic Lofgren Hayes as more important to popular music concert history than was any other single performance up to that point--->this is logical

interpretation 2 :a performance described by critic Lofgren Hayes as more important to popular music concert history than to any other single performance up to that point---->this is no sense !!

kindly share the source

Hi,

the source is my online gmat course.

It was a sentence correction question. And in my opinion we need to put was after than so It should be as follows; a performance described by critic Lofgren Hayes as more important to popular music concert history than was any other single performance up to that point

but according to the answers the sentence is correct without "was".

I am pretty confused..

aditya8062 wrote: a performance described by critic Lofgren Hayes as more important to popular music concert history than any other single performance up to that point."

there is no ambiguity in the sentence as it stands now !!
this is mainly because the other interpretation is making no sense.the 2 interpretation that can come out are as follows :
interpretation 1 :a performance described by critic Lofgren Hayes as more important to popular music concert history than was any other single performance up to that point--->this is logical

interpretation 2 :a performance described by critic Lofgren Hayes as more important to popular music concert history than to any other single performance up to that point---->this is no sense !!

kindly share the source

it was a sentence correction question. And in my opinion we need to put was after than so It should be as follows; a performance described by critic Lofgren Hayes as more important to popular music concert history than was any other single performance up to that point

well as i have said we don't need "was"
also note that here u are making a comparison between "a performance" and "any other single performance up to that point ". in fact this construction :a performance described by critic Lofgren Hayes as more important to popular music concert history is not even a clause !! so all u need after "than" is just "any other single performance up to that point" .that means if u put "was" u will effectively make it a clause there by making this comparison faulty