Opiate is the first tool album. I was familiar with other tool albums such as undertow and AENIMA before getting opiate. Upon hearing it for the first time, I knew that Opiate marked the beginnings of a great band. All the songs are great, espcially the live tracks-cold and ugly and jerk off. Opiate does help provide an important piece in the tool chronology showing how the band evolved from Opiate to Lateralus.