The music from The Lord of the Rings films is to be given its live US premiere by an orchestra conducted by composer Howard Shore on Friday.
Howard Shore recently won Oscars for best score and best song
The Columbus Symphony Orchestra, from Ohio, will stage the two-hour show in six movements - two for each film - with 200 performers on stage.
They include two choirs who have had to learn songs in invented languages.
The 5,500 tickets for the Friday concert have been sold out, and another show has been added on Saturday.
The orchestra agreed to play Shore's score to the award-winning films two years ago - before Shore had finished it.
Shore has already conducted renditions in New Zealand, for the Return of the King premiere in December, and in his native Canada.
"We're always on the prowl for new and interesting projects," said Dan Hart, symphony president and executive director.
"It seemed like a perfect opportunity to introduce the symphony to a whole different group of people."
As well as the normal orchestra performers, other musicians will play Norwegian fiddle and Japanese drums, while others will rattle chains.
The music has been voted the top soundtrack in movie history
Fans of Shore's music from as far away as Alaska and Paris are expected to travel to Ohio to see the concerts.
Other performances of the Rings music are due to take place in Antwerp, London, Atlanta, Philadelphia, Seattle and Pittsburgh.
"It's somewhat of a community educational event," Shore said. "In Montreal, I saw lots of Lord of the Rings books around [at rehearsals].
"The piece is essentially also based in 19th Century symphonic tradition," he said. "You wanted to create a piece that was steeped in antiquity.
"The book is so musical, you wanted to have some aspect of that writing in the film."