The band had previously written an orchestral-style piece in the form of "Overture" on "Six Degrees of Inner Turbulence", but recorded it using keyboards. The tracks "The Answer Lies Within", "Sacrificed Sons" and "Octavarium" marked the first time Dream Theater worked with an orchestra, conducted by Jamshied Sharifi (who studied at Berklee College of Music at the same time as Portnoy, Petrucci and bassist John Myung). The orchestra was selected based on their sight reading ability, allowing all their parts to be recorded in a maximum of two takes, even though they had never seen or played the music before.