The new school of hip hop marks the second major period in the development of the genre. By the time of the movement’s inception, around 1983, hip hop was already highly popular. However, with the release of the two tracks It’s Like That and Sucker MCs, Run-D.M.C. developed a rawer sound consisting of a more aggressive rap style and a stripped-down backing track, mainly produced by a drum machine. In 1984, they released their eponymous debut LP which is considered a hallmark of hip hop. Two years later Run-D.M.C. followed up with Raising Hell, a highly successful record that was equally influential, containing the Aerosmith crossover, Walk This Way. Integral to the production of Raising Hell were Rick Rubin and Russell Simmons, both of whom were co-owners of Def Jam Recordings. This label proved very important and released music by LL Cool J and the Beastie Boys.