Critic Philip Auslander argues that the distinction between pop and rock is more pronounced in the US than in the UK. He claims in the US, pop has roots in white crooners such as Perry Como, whereas rock is rooted in African-American music influenced by forms such as rock and roll. Auslander points out that the concept of pop rock, which blends pop and rock is at odds with the typical conception of pop and rock as opposites. Auslander and several other scholars such as Simon Frith and Grossberg argue that pop music is often depicted as an inauthentic, cynical, "slickly commercial" and formulaic form of entertainment. In contrast, rock music is often heralded as an authentic, sincere, and anti-commercial form of music, which emphasizes song writing by the singers and bands, instrumental virtuosity, and a "real connection with the audience".

Simon Frith's analysis of the history of popular music from the 1950s to the 1980s has been criticized by B. J. Moore-Gilbert, who argues that Frith and other scholars have over-emphasized the role of "rock" in the history of popular music by naming every new genre using the "rock" suffix. Thus when a folk-oriented style of music developed in the 1960s, Frith terms it "folk rock", and the pop-infused styles of the 1970s were called "pop rock". Moore-Gilbert claims that this approach unfairly puts rock at the apex, and makes every other influence become an add-on to the central core of rock.

Softer sounds in rock music could be heard in mid-1960s songs, such as "Here, There and Everywhere" by the Beatles and "I Love My Dog" by Cat Stevens, both from 1966.

By 1968, hard rock had been established as a mainstream genre. From the end of the 1960s, it became common to divide mainstream rock music into soft and hard rock,with both emerging as major radio formats in the US.Late 1960s soft rock artists included the Bee Gees, whose song "I Started a Joke" was a number one single in several countries; Neil Diamond with the 1969 hit "Sweet Caroline", the Hollies with their U.S. and UK Top 10 hit "He Ain't Heavy, He's My Brother", and Elton John with his popular song "Skyline Pigeon".

By the early 1970s, softer songs by the Carpenters, Anne Murray, John Denver, Barry Manilow, and even Barbra Streisand began to be played more often on "Top 40" radio and others were added to the mix on many adult contemporary stations.

Major artists of that time included Barbra Streisand, Carole King, Cat Stevens, James Taylor and Bread.

The Hot 100 and Easy Listening charts became more similar again toward the end of the 1960s and into the early and mid-1970s, when the texture of much of the music played on Top 40 radio once more began to soften. The adult contemporary format began evolving into the sound that later defined it, with rock-oriented acts as Chicago, the Eagles and Elton John becoming associated with the format. The Carpenters' hit version of "(They Long to Be) Close to You" was released in the summer of 1970, followed by Bread's "Make It with You", both early examples of a softer sound that was coming to dominate the charts.

The soft rock album Tapestry by Carole King, released in February 1971, became one of the best-selling albums of all time.

Los Angeles station KNX-FM, under program director Steve Marshall, introduced a "mellow rock" format in 1971.

Soft rock reached its commercial peak in the mid- to late 1970s with acts such as Toto, England Dan & John Ford Coley, Air Supply, Seals and Crofts, America and the reformed Fleetwood Mac, whose Rumours (1977) was the best-selling album of the decade.

Denver station KIMN-FM introduced a "mellow rock" album format in 1975. "There's a Colorado music," program director Scott Kenyon told Billboard magazine, "Michael Murphey's 'Wildfire' is a perfect example; it feels like Colorado, you can tell it came from this part of the country. There's a sound of the Rockies... the best description is mellow rock. Take that kind of music and make it into a Colorado sounding station."

By 1977, some radio stations, notably New York's WTFM and NBC-owned WYNY, had switched to an all-soft rock format.Chicago's WBBM-FM adopted a soft rock/album rock hybrid format in 1977 and was known as "Soft Rock 96" presenting the "Mellow sound of Chicago." Five years later they would flip to a "Hot Hits" Top 40 format.

In the mid- to late 1970s, prominent soft rock acts included Billy Joel, Elton John, Jefferson Starship, Chicago, Toto, Boz Scaggs, the Alessi Brothers, Michael McDonald, England Dan & John Ford Coley, Paul Davis, Air Supply, Seals and Crofts, the Doobie Brothers, Captain & Tennille, the Hollies, America, and Fleetwood Mac.

By the 1980s, tastes had changed and radio formats reflected this change, including musical artists such as Journey.

, leading to the conflation

1980s

In the early 1980s, the radio format evolved into what came to be known as "adult contemporary" or "adult album alternative", a format that has less overt rock bias than its forebear radio categorization.Although dance-oriented, electronic pop and ballad-oriented rock dominated the 1980s, soft rock songs still enjoyed mild success thanks to Sheena Easton, Ambrosia, Lionel Richie, Christopher Cross, Dan Hill, Leo Sayer, Billy Ocean,Julio Iglesias and Bertie Higgins.