Radio content in the Golden Age of Radio had its origins in audio theatre. Audio theatre began in the 1880s and 1890s with audio recordings of musical acts and other vaudeville. These were sent to people by means of telephone and, later, through phonograph cylinders and discs. Visual elements, such as effects and sight gags, were adapted to have sound equivalents. In additions, visual objects and scenery were converted to have audio descriptions.

On Christmas Eve, 1906, Reginald Fessenden sent the first radio program broadcast, which was made up of some violin playing and passages from the bible. At least one radio researcher has questioned whether this broadcast took place, because it was not mentioned in print until many years later. Then, after the Titanic catastrophe in 1912, radio for communications went into vogue. Radio was especially important during World War I, since it was a primary source of communication for both sides. Then, after the war and before radio regulation, numerous radio stations began starting up and setting the standard for later radio programs.

The first radio news program was broadcast on August 31, 1920 on the station 8MK in Detroit, Michigan. This was followed in 1920 with the first commercial radio station in the United States, KDKA, being established in Pittsburgh, Pennsylvania. In 1922, the first regular entertainment programs were broadcast. A highlight of this time was the first Rose Bowl being broadcast on January 1, 1923 on the Los Angeles station KHJ.

During the Golden Age of Radio, radio featured genres and formats popular in other forms of American entertainment—adventure, comedy, drama, horror, mystery, musical variety, romance, thrillers—along with classical music concerts, big band remotes, farm reports, news and commentary, panel discussions, quiz shows, sidewalk interviews, sports broadcasts, talent shows and weather forecasts.

In the late 1920s, the sponsored musical feature was the most popular program format. Commercial messages were regarded as intrusive, so these shows usually displayed the sponsor's name in the title, as evidenced by such programs as The A&P Gypsies, Acousticon Hour, Champion Spark Plug Hour, The Clicquot Club Eskimos, The Flit Soldiers, The Fox Fur Trappers, The Goodrich Zippers, The Ingram Shavers, The Ipana Troubadors, The Planters Pickers, The Silvertown Cord Orchestra (featuring the Silver Masked Tenor), The Sylvania Foresters and The Yeast Foamers. During the 1930s and 1940s, the leading orchestras were heard often through big band remotes, and NBC's Monitor continued such remotes well in the 1950s by broadcasting live music from New York City jazz clubs to rural America.

Classical music programs on the air included The Voice of Firestone and The Bell Telephone Hour. The Metropolitan Opera was also featured in weekly broadcasts of complete operas, then sponsored by Texaco. The broadcasts, now sponsored by the Toll Brothers, continue to this day on NPR and are one of the few examples of live classical music still broadcast on radio. One of the most notable of all classical music radio programs of the Golden Age of Radio featured the celebrated Italian conductor Arturo Toscanini conducting the NBC Symphony Orchestra, which had been created especially for him. At that time, nearly all classical musicians and critics considered Toscanini the greatest living maestro. There were also popular songwriters featured on radio, such as George Gershwin, who in addition to appearing as a guest, also had his own program in 1934.

Top comedy talents surfed the airwaves for many years: Fred Allen, Jack Benny, Victor Borge, Fanny Brice, Billie Burke, Bob Burns, Judy Canova, Jimmy Durante, Phil Harris, Bob Hope, Groucho Marx, Jean Shepherd, Red Skelton and Ed Wynn. More laughter was generated on such shows as Abbott and Costello, Amos 'n' Andy, Burns and Allen, Easy Aces, Ethel and Albert, Fibber McGee and Molly, The Goldbergs, The Great Gildersleeve, The Halls of Ivy (which featured screen star Ronald Colman and his wife Benita Hume), Meet Corliss Archer, Meet Millie, and Our Miss Brooks.

Radio comedy ran the gamut from the small town humor of Lum and Abner, Herb Shriner and Minnie Pearl to the dialect characterizations of Mel Blanc and the caustic sarcasm of Henry Morgan. Gags galore were delivered weekly on Stop Me If You've Heard This One and Can You Top This?, panel programs devoted to the art of telling jokes. Quiz shows were lampooned on It Pays to Be Ignorant, and other memorable parodies were presented by such satirists as Spike Jones, Stoopnagle and Budd, Stan Freberg and Bob and Ray. British comedy reached American shores in a major assault when NBC carried The Goon Show in the mid-1950s.

Some shows originated as stage productions: Clifford Goldsmith's play What a Life was reworked into NBC's popular, long-run The Aldrich Family (1939-1953) with the familiar catchphrases "Henry! Henry Aldrich!", followed by Henry's answer, "Coming, Mother!". Moss Hart and George S. Kaufman's Pulitzer Prize-winning Broadway hit, You Can't Take It with You (1936), became a weekly situation comedy heard on Mutual (1944) with Everett Sloane and later on NBC (1951) with Walter Brennan.

Other shows were adapted from comic strips, such as Blondie, Dick Tracy, Gasoline Alley, The Gumps, Li'l Abner, Little Orphan Annie, Popeye the Sailor, Red Ryder, Reg'lar Fellers, Terry and the Pirates and Tillie the Toiler. Bob Montana's redheaded teen of comic strips and comic books was heard on radio's Archie Andrews from 1943 to 1953. The Timid Soul was a 1941-1942 comedy based on cartoonist H.T. Webster's famed Casper Milquetoast character, and Robert L. Ripley's Believe It or Not! was adapted to several different radio formats during the 1930s and 1940s.

When daytime serials began in the early 1930s (the first soap opera was introduced in 1930 on Chicago's WGN), they became known as soap operas because many were sponsored by soap products and detergents. The line-up of late afternoon adventure serials included Bobby Benson and the B-Bar-B Riders, The Cisco Kid, Jack Armstrong, the All-American Boy, Captain Midnight, and The Tom Mix Ralston Straight Shooters. Badges, rings, decoding devices and other radio premiums offered on these adventure shows were often allied with a sponsor's product, requiring the young listeners to mail in a box top from a breakfast cereal or other proof of purchase.

Outstanding radio dramas were presented on such programs as 26 by Corwin, NBC Short Story, Arch Oboler's Plays, Quiet, Please, and CBS Radio Workshop. Orson Welles's Mercury Theatre on the Air and Campbell Playhouse were considered by many critics to be the finest radio drama anthologies ever presented. They usually starred Welles in the leading role, along with celebrity guest stars such as Margaret Sullavan or Helen Hayes, in adaptations from literature, Broadway, and/or films. They included such titles as Liliom, Oliver Twist, A Tale of Two Cities, Lost Horizon, and The Murder of Roger Ackroyd. It was on Mercury Theatre that Welles presented his celebrated-but-infamous adaptation of H.G. Wells's The War of the Worlds, formatted to sound like a breaking news program.

Lux Radio Theater and The Screen Guild Theater presented adaptations of Hollywood movies, performed before a live audience, usually with cast members from the original films. Suspense, Escape, The Mysterious Traveler and Inner Sanctum Mysteries were popular thriller anthology series. Leading writers who created original material for radio included Norman Corwin, Carlton E. Morse, David Goodis, Archibald MacLeish, Arthur Miller, Arch Oboler, Wyllis Cooper, Rod Serling and Irwin Shaw.