Classic rock was originally conceived as a radio station broadcasting format and although loosely defined, it generally includes the music from rock bands formed between the early 1960's and 1990. The most common classic rock band line-up is a, lead singer, lead guitar player, a rhythm guitar player, a bass guitar player, and a drummer, although many bands also feature a keyboardist, at least on some tracks.
Concept albums are a major part of classic rock, and there are many available. Amongst the prime examples are probably the four Pink Floyd concept albums, including The Wall and Dark Side of the Moon. The Beatles famed Sgt. Pepper's Lonely Hearts Club Band is another prime example.
'Classic rock' began as a broadcasting format on AM radio in an attempt to retain listeners. One of the first AM stations to adopt this style of programming with the attempted introduction of AM stereo broadcasting, was KRQX in Dallas, Texas where George Gimarc played a leading role in its introduction. The Classic rock format has now been adopted by FM radio. In the United States this rock music format now features a limited playlist of songs ranging from early 1970s album tracks to current songs by artists associated with the loosely defined "classic rock era". It is an outgrowth of the Album-Oriented Rock (or AOR) format popular in the 1970s and 1980s.
Classic rock is also a term used to mean a fusion of classical and rock music, or more usually, rock music arranged for and played by a symphony orchestra and is consequently also called Symphonic rock. The style was popularised by a series of albums called "Classic Rock", "Classic Rock 2", etc. performed by the London Symphony Orchestra in the 1970s. The resulting easy listening albums sold well and were popular until the early 1980s, when the form seemed to fall out of favour with the public. The LSO even scored a hit single with a medley of Classic Rock called Hooked on Classics, in 1981, though whereas the earlier albums were "classical" arrangements of hits by such artists as the Rolling Stones, The Beatles, Nilsson and others, Hooked on Classics took the opposite tack - arranging a series of well-known classical pieces into a medley with a common tempo and adding a rock drumming track. The medley form was briefly popular around that time due to artists such as Stars on 45.
There have also been a number of popular songs based on classical music - see List of popular songs based on classical music.