AOR (Adult Oriented Rock) is a sub-genre of Rock that emerged in the late 1970s and early 1980s as an amalgamation of Rock, Hard Rock and Progressive Rock. It is characterized by a rich, layered sound, slick production and a heavy reliance on pop/rock hooks, which led to its huge popularity in the late 1970s and early 1980s. Adult-oriented rock is distinguished from the US "album-oriented rock" FM radio format, also called AOR, which played not only adult-oriented rock but also album tracks and "deep cuts" from a variety of other rock genres.
AOR songs are almost always synthesizer driven and catchy and very often include harmonized vocals. The catchy choruses combined with relatively short song lengths make AOR a very radio friendly genre. The songs are more melodic than straight-ahead, regular Hard Rock, but still not nearly as light as Pop Rock.
Some of the earliest - and also the most well known - AOR bands include names like Asia, Boston, Foreigner, Journey, Survivor and Toto.
Although AOR experienced a decline in popularity in the 1990s, there has been a resurgence in recent years. Some of the notable groups in this later era include Brother Firetribe, Frederiksen/Denander, Place Vendome and Pride of Lions. .