When I saw the musical, one thing really surprised me was the size of orchestra in the theater. It was a really tiny space compering other musical orchestra boxes. In the teather, the conductor had the first piano, and there was the second piano in front of the conductor, some brass instruments, wind instruments, (I waved at a flute player during the intermission) and very simple electronic equipment. At first I guessed that the musicians used both the recording piece and live orchestra.
Today, the Book of Mormon's homepage posted interesting Youtube video clips of music episodes. The composers created music to play only nine musicians to sound like a full orchestra. I love their Eco-quality-concept! And I really understand that how important it is to create a great and smart score with minimum players. The minimum in this case can create something greater.
I thought that it was not original enough for the music when I was watching the musical; however, I might change my mind after I listen to their CD more.
Because the story line was very contemporary and wild in a way, the composer might choose familiar sounds and harmonies to reflect everyone's favorite classic musicals. Therefore, the story line needed the conservative, already existing tones. If the music was too contemporary like the story line, the audience may not accept the musical well.
My current favorite musics are "Hello!" and "Turn it Off." They are very original pieces in the musical. And of course, I love to say, “Hasa Diga Eebowai.” (My husband likes "Spooky Mormon Hell Dream" the most.)