Mainstream rock stations are between classic rock and active rock on the programming spectrum, in that they play more classic rock songs focusing in on the 1970s, 1980s and the 1990s than active rock stations, but play a balanced airplay of New and recent artists found on Active Rock playlists but more songs closely related to classic rock stations. Mainstream rock is a successor to the widespread album-oriented rock (AOR) format created in the 1970s... Mainstream Rock can be used as a modern lean of classic rock on the basis if the playlist has to cut back some Active Rock artists and songs due to ratings and popularity issues... Some may consist of playing 1970's all the way to the 1990's and others might adopt the 1960's and make it blended in.
As of 2013[update], some examples of mainstream rock stations in terrestrial radio include: KSHE/St. Louis, MO, KEGL/Dallas, TX, KRXQ/Sacramento, CA, KISS/San Antonio, TX, KDKB/Phoenix, AZ, KBER/Salt Lake City, UT, WDVE/Pittsburgh, PA, WHQG/Milwaukee, WI, WFYV-FM/Jacksonville, FL, CJAY/Calgary, Alberta, WAPL/Appleton, WI, KZRR/Albuquerque, NM, KEZO/Omaha, NE, WHJY/Providence, RI, KICT/Wichita, KS, KMOD/ Tulsa, OK, KTUX/Shreveport, LA, KZEL/Eugene, OR, and WIYY/Baltimore, MD. Most have a very long heritage that dates back to the 1970s as AOR stations, which is why several trades like Billboard and R&R will refer these stations as "Heritage Rock".
Outside of the United State and Canada, mainstream rock refers generally to rock music deemed 'radio friendly'. It very rarely is referred to as a specific radio format.