2001 (Dr. Dre album) were later cut from the final track list. The tracks have been leaked later on several mixtapes, including "Pretox". The album's production expanded on that of "The Chronic", with new, sparse beats and reduced use of samples which were prominent on his debut album. Co-producer Scott Storch talked of how Dr. Dre used his collaborators during recording sessions: "At the time, I saw Dr. Dre desperately needed something. He needed a fuel injection, and Dre utilized me as the nitrous oxide. He threw me into the mix, and I sort of tapped on a new flavor with my whole piano
Dr. Dre can control it better." Other equipment he uses includes the E-mu SP-1200 drum machine and other keyboards from such manufacturers as Korg, Rhodes, Wurlitzer, Moog, and Roland. Dr. Dre also stresses the importance of equalizing drums properly, telling Scratch magazine in 2004 that he "used the same drum sounds on a couple of different songs on one album before but you'd never be able to tell the difference because of the EQ." Dr. Dre also uses the digital audio workstation Pro Tools and uses the software to combine hardware drum machines and vintage analog keyboards and synthesizers. After founding Aftermath