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 Entertainment in 1996, Dr. Dre took on producer Mel-Man as a co-producer, and his music took on a more synthesizer-based sound, using fewer vocal samples (as he had used on "Lil' Ghetto Boy" and "Let Me Ride" on "The Chronic", for example). Mel-Man has not shared co-production credits with Dr. Dre since approximately 2002, but fellow Aftermath producer Focus has credited Mel-Man as a key architect of the signature Aftermath sound. In 1999, Dr. Dre started working with Mike Elizondo, a bassist, guitarist, and keyboardist who has also produced, written and played on records for female singers such as Poe,