The MOR genre creation was an evolutionary outcome of WNEW's reluctance to follow the Top 40 domination and adhere to traditional male and female vocals such as Frank Sinatra, Tony Bennett, Ella Fitzgerald and Peggy Lee.
Soft rock groups like the Association, the 5th Dimension, the Bee Gees, the Johnny Mann Singers and Simon & Garfunkel infiltrated the MOR market in the late 1960s.
"[3] The middle of the road music category has traditionally included these genres: As an AM radio format in the United States and Canada, MOR's heyday was the 1960s and the 1970s.
[10] Artists such as Westlife (pop),[11] Kenny Rogers (country)[12] and Train (rock)[13] are considered middle of the road.
",[15] while on a later review of Coldplay's X&Y, Pitchfork writes that: "U2 recorded 'I Will Follow', 'New Year's Day', 'Bad', and The Joshua Tree, among others, before they wandered off into the MOR wilderness.