Guitarist John Petrucci told Ultimate-Guitar.com
that it was inconceivable that the band couldn't have made the album without his JP13 guitar. He explained: "In a rock band or a metal band whatever, the guitar sounds kind of dictates the way the album is gonna sound. Because it's a featured instrument and it takes up so much and it will sort of shape the direction and overall sound of the song. If it's really heavy, percussive and aggressive, that's the way the song is gonna sound. It's a very powerful instrument because it dictates the landscape you're setting up. So that guitar and especially the 7-string version of it. I used on a lot of songs on the album. You can hear it on the instrumental 'Enigma Machine' and when that 7-string comes in it's just so heavy and huge. That couldn't have been done with another instrument - it had to sound like that."