It's a Sing-Along - so in the span of about 1/2 hour, the entire score from the movie Frozen can/will be sung by audience members.
To move you through the time, there are two comedians, introduced as Royal Historians, who narrate the Frozen story from beginning to end while also bringing the audience to the point of singing each consecutive tune.
My wife & I found it very amusing. The only criticism would be that some people (adults and children alike) might not make into their Choir and might consider toning down their exuberance.
Frankly, after reading some of the criticisms before we first saw the show, we could only conclude after the fact that those people who did not enjoy it have no sense of humor and/or had never seen the movie.