Mainstream jazz is a term coined in the 1950s by music journalist Stanley Dance, who considered anything within the popular jazz of the Swing Era "mainstream",^[1] and did not include the bebop style.

After Dance defined mainstream jazz in the 1950s, the definition changed with the evolution and progression of jazz music. What was mainstream then would not be considered mainstream now. In a general sense, mainstream jazz can be considered what was most popular at the time: For example, during the Swing era, swing and big band music were in their prime and what target audiences were looking for. Although bebop was introduced into jazz during that time, audiences had not developed an ear for it.^[1]

In the 1950s and 1960s, jazz was a mainstream part of pop culture. Jazz music was on the radio and Hollywood frequently incorporated jazz in television and films.^[6]