 Many stations also set aside a block of programming for golden oldies, or music from the 1920s through early 1960s, with genres ranging from early rock and roll and pre-1965 country music to pop standards, swing, jazz, big band and – sometimes – existing recordings predating the 1920s.Full-service radio was the predominant form of radio broadcasting during the network radio era, before the debut of contemporary hit radio (top 40) in the 1950s.In the old-time radio era, most stations would mix local programs (of a wide variety) with the networks' offerings.