Arena Rock developed in the mid-'70s, when hard rock and heavy metal bands began to gain popularity. The music became more commercially oriented and radio-friendly, boasting slick productions and anthemic choruses, both on their hard rock numbers and their sweeping power ballads. Most of these bands earned their following through saturation airplay on FM radio and through constant touring. Bands like Journey, REO Speedwagon, Boston, Foreigner, and Styx became some of the most popular bands of the mid- to late '70s through this circuit.