Dream Theater drummer Mike Portnoy was listed as a full member of OSI on the first album, but found working on the first album to be a difficult experience. Moore noted that Portnoy "wasn't used to having other people have strong ideas about what the drum parts should be". For "Free", Portnoy contributed drum tracks as a session musician, agreeing to "take and Moore's ideas and do the best he could with playing", according to Moore. Portnoy's drum parts were recorded at Carriage House Studios in Stamford, Connecticut from November 18 to November 20, 2005.