Follies is arguably the hardest Stephen Sondheim musical to stage. The score and book are strong, but the technical requirements of the show are very high. The musical takes place in a crumbling Broadway theater about to be demolished. A group of performers from the Weismann's Follies are reuniting. They haven't performed their show since before both of the World Wars and are shocked by the condition of their old home. Now just imagine trying to mount a musical where the set is a formerly lush and desirable theater falling apart. You not only have to design a gigantic stage, you have to destroy it as well.
Then go further into the challenge of the show. There are two distinct scores happening at the same time. The songs happening in the actual narrative of the show--the reunion--are on in one style, while the songs performed by the characters at the reunion--the old show numbers--are in a completely different style. Meaning, a bunch of show girls and chorus members are arriving to reunite in less than ideal circumstances and performing the songs that haven't been in style for 40 years. It's a tricky balance with big production numbers that is hard to find.
Though the original production ran over 500 performances on Broadway, the show ultimately lost money because of the demands of the production. It also split the critics when it opened for being just so different. It's well-remembered now and revived with elaborate productions on occasion at regional theaters. The most recent revival at The Kennedy Center--starring Bernadette Peters, Jan Maxwell, Danny Burstein, Ron Raines, and Elaine Paige--closes in 3 days in Washington, D.C.. However, it is going to transfer to Broadway by the end of the summer for a limited engagement. The cast is phenomenal and the critics raved about the production. This will be a fall theatrical event not to be missed.