Hard rock Styx helped further cement heavy rock in the Midwest as a form of stadium rock. In 1978, Van Halen emerged from the Los Angeles music scene with a sound based around the skills of lead guitarist Eddie Van Halen. He popularised a guitar-playing technique of two-handed hammer-ons and pull-offs called tapping, showcased on the song "Eruption" from the album "Van Halen", which was highly influential in re-establishing hard rock as a popular genre after the punk and disco explosion, while also redefining and elevating the role of electric guitar. The opening years of the 1980s saw a number of changes
Hard rock some of which were influenced by hardcore punk, and which further differentiated the two styles. Despite this differentiation, hard rock and heavy metal have existed side by side, with bands frequently standing on the boundary of, or crossing between, the genres. The roots of hard rock can be traced back to the 1950s, particularly electric blues, which laid the foundations for key elements such as a rough declamatory vocal style, heavy guitar riffs, string-bending blues-scale guitar solos, strong beat, thick riff-laden texture, and posturing performances. Electric blues guitarists began experimenting with hard rock elements such as driving rhythms, distorted guitar