Hard rock (or heavy rock) is a loosely defined genre of rock music which has its earliest roots in mid-1960s garage rock, blues rock and psychedelic rock. It is typified by a heavy use of distorted electric guitars, bass guitar, drums, and often accompanied with pianos, and keyboards.
Hard Rock developed into a major form of popular music in the 1970s, with bands like Led Zeppelin, Deep Purple, Aerosmith, AC/DC and Van Halen, and reached a commercial peak in the mid 1980s. The glam metal of bands like Bon Jovi and Def Leppard and the rawer sounds of Guns N' Roses followed up with great success in the later part of that decade, before losing popularity in the face of grunge. Despite this, many post-grunge bands adopted a hard rock sound and in the 2000s there came a renewed interest in established bands, attempts at a revival, and new hard rock bands that emerged from the garage rock and post punk revival.
Southern rock is a subgenre of rock music, and genre of Americana. It developed in the Southern United States from rock and roll, country music, and blues, and is focused generally on electric guitar and vocals. Although no one really knows where the term southern rock came from, "many people feel that these important contributors to the development of rock and roll have been minimized in rock’s history.