When
FM broadcasting licenses were first issued by the
FCC, broadcasters were slow to take advantage of the new airwaves available to them because their advertising revenues were generated primarily from existing
AM broadcasting stations and because there were few FM radio receivers owned by the general public. This void created an opportunity for the disenchanted youth of the
counterculture of the 1960s and their counterparts,
Hippies and
Flower Children, to express themselves by playing music that was largely ignored by mainstream outlets. In this sense, progressive rock radio was more of a social response than a product marketed to fill a need. Inasmuch as the format was commercial, underground sought to capitalize on the maturing of the
Baby Boomers who were growing out of the
top 40 radio of their youth, which was still targeting teens. This change coincided with the greater emphasis on
albums as opposed to
singles in the rock market. Underground stations clearly disdained
Top 40 music and made it a policy to avoid playing it. A dilemma grew because many underground artists were contractually obligated to release a certain amount of singles and FCC regulations required such songs to be 3 minutes long, or less. These "single versions" were often quite different than what was on the originating albums. Underground radio could liberally play what were referred to as "the album versions" of songs, no matter how long they were. By the same token, hugely popular and successful albums such as
The Beatles' ''
Sgt. Pepper's Lonely Hearts Club Band'' and
Arlo Guthrie's ''
Alice's Restaurant'' did not contain any singles. In fact, the actual song "
Alice's Restaurant" is the entire Side A of its titular album, coming in at over 18 minutes, making it way over the 3-minute mandate, grew to fame in part because of persistent airplay from underground radio host
Bob Fass, and later became a
Thanksgiving tradition on other underground/progressive stations. Many DJs at underground stations also chose to play entire sides of albums that contained multiple tracks, which could range from 20 to 30 minutes. At that time, these actions were considered very bold, so there was clearly a need for a radio format that could not only explore beyond the
Top 40, but be allowed to do so with the DJs leading the way. This in turn led to established and new rock artists placing greater emphasis on long or experimental album tracks, knowing they would receive radio airplay. ==Definition==