World War II led to a sharp increase in all-night radio programming. Feeling it their patriotic duty, many stations (among them WNAC and WEE! in Boston, WNEW and WOR in New York, WKBW in Buffalo, KDKA in Pittsburgh, WCAU in Philadelphia, and WRVA in Richmond) offered broadcasts for those legions of Americans working graveyard shifts in defense plants and factories.

     After the war, all-night talk shows began to appear. Regarded by many as the father of the overnight call-in show, Barry Gray launched his program in New York City in 1945, and his "graveyard gab-a-thons" would remain among the most popular forms of this radio programming daypart. In the 1970s, all-night talk was given a significant boost with the debut of national call-in shows hosted by personalities such as Larry King and other extremely popular and sometimes controversial talkmasters. The use of toll-free 800 numbers enhanced the attraction of this format.

     The primary appeal of overnight radio broadcasting lies in its companionability. A 1968 National Association of Broadcasters survey concluded that 60 percent of the all-night audience tunes in to keep from being lonely. All-night radio is also where the subcultures and countercultures tune to stay connected at an hour when the mainstream world is asleep. Insomniacs and third-shift workers, among them bakers, policemen, cab drivers, and convenience store clerks, constitute a substantial part of the loyal listenership of all-night radio. For aspiring disc jockeys and talk hosts, the overnight shift frequently serves as a training ground. It is where stations often put their most inexperienced on-air people to allow them the chance to build their skills. However, for some seasoned professionals, especially those in larger markets, the overnight shift is a preferred slot, because it is a segment of the program clock when rigid compliance to format strictures may be somewhat relaxed, thus providing them with greater opportunity to experiment and flex their creative muscles.

     The program content of all-night radio tends to be eclectic. However, since the 1980s there has been a significant rise in the number of stations airing overnight talk shows, often syndicated programs, and canned programming is :widely employed to fill the time slot. This period of the broadcast schedule has become famous for an often bizarre mix of program offerings. Psychics, paranormalists, conspiracy theorists, love therapists-to mention a few-are among the unique array of those who hold court over the night-time airwaves at hundreds of radio stations.

     Outlets programming music over nights are frequently equally divergent in their approaches. In fact, music stations that feature a primary or single format during the day may shift gears to another, albeit complementary, form of music for their overnight hours. One quality many all-night music stations share in common is their tendency to soften or mellow their sounds to create a mood and atmosphere consonant with the nocturnal landscape. Jazz, blues, folk, and classical music are frequently given more airplay at night than during the day. Of course, not all stations vary or reconfigure their program clocks or playlists between midnight and 6 A.M. In fact, most actually mirror the programming they offer throughout the day and early evenings.

     No programming ingredient has been more responsible for establishing loyal overnight followings than the radio personality; many of these have served their audiences for decades. The list of popular all-night hosts is long, if not endless. A partial list would certainly include Jean Shepherd, Norm Nathan, Franklin Hobbs, Joey Reynolds, Larry King, Henry Morgan, Jerry Williams, Jim Bohannon, Joe Franklin, Bany Farber, Larry Glick, Alison Steele, Ira Fistell, Ray Briem, Herb Jepko, Jean King, Larry Regan, Raechel Donahue, Long John Nebel, Wolfman Jack, Barry Gray, Mary Turner, Eddie Schwartz, John Luther, Mel Lindsay, Rollye James, Stan Shaw, Art Dineen, Hunter Hancock, Doug Stephan, Yvonne Daniels, Al Collins, Don Sainte John, Tom Snyder, Dave Wiken, and Art Ford. Every late-night listener has his or her favorite personality. Perhaps no all-night figure was more popular than Art Bell at the turn of the millennium. Broadcasting from a remote locale (near the infamous "Area 51 ") in the Nevada desert, Bell attracted an audience that consistently numbered in the millions from coast to coast.

     Since 1988, Arbitron has rated overnight time slots at the behest of outlets in markets with potentially large listenerships during this segment of the broadcast schedule. Although all­ night hours are not typically viewed as profit centers (in fact, they are more often thought of as "giveaway" zones), many stations have been successful enough in generating revenues to want audience statistics to help promote increased levels of advertising. In fact, the value of all-night radio as an advertising medium has risen in• a world that has become increasingly 24-hour oriented.

     With the predicted continuation of station consolidation and an even greater bottom-line emphasis, live and local all­ night programming is expected to decline in the future. It is not unusual to find stations rebroadcasting daytime programs during their overnight hours, and the rise in bartered and syndicated shows is significant. Although the prospects for all-night radio are far from bleak, its growth will likely be influenced, if not substantially inhibited, by ongoing industry downsizing and the increasing reliance of the listening public on new forms of electronic media, such as the internet and digital audio on demand. Meanwhile, the program fare (politics and other hot­ button issues) that has attracted all-night listeners for so many years appears to be on the wane, increasingly replaced by features that are far less provocative and controversial and thus more salable to advertisers.