Radio

How radio works

Antennae tune a radio to a particular frequency (determined by the listener on their radio's dial) while tuning out all the other stations being broadcast. AM, short for amplitude modulation, and FM, short for frequency modulation, decode audio signals differently, leading to differences in sound quality and the distance a station can travel.

The disputed inventor of the radio

Guglielmo Marconi was awarded the 1909 Nobel Prize in physics for inventing the wireless telegraph, which used radio waves to transmit Morse code. Nikola Tesla, however, was experimenting with radio waves in the 1890s, though much of his work was destroyed in a 1895 fire.

See a timeline of commercial radio history

Radio, as we know it, began in the 1910s. This FCC timeline traces the evolution of the medium over the century that followed, highlighting groundbreaking broadcasts, speeches, and technological breakthroughs.

Many scholars consider the first commercial radio broadcast to be during the 1920 presidential election

On Nov. 2, Pittsburgh, Pennsylvania, station KDKA broadcast the results of the presidential election. Leo Rosenberg delivered the news that Warren Harding had won in a landslide to an audience of around 100 people.

The start of commercial radio depends on how someone defines the word 'commercial.'

Calvin Coolidge brought the State of the Union to the radio age

On Dec. 6, 1923, President Coolidge delivered his Annual Message from the US House chamber as millions listened by radio—crowds gathered outside with amplifiers—making it the first nationally broadcast address and the only in-person State of the Union of his presidency.

'The Grand Ole Opry' radio show debuted in 1925

The Grand Ole Opry began as "The WSM Barn Dance," broadcasting from downtown Nashville. The name changed when its host, transitioning from the station's previous program, said, "You've been up in the clouds with Grand Opera; now get down to earth with us in a shindig of Grand Ole Opry!"

Explore 'The Grand Ole Opry' radio archive

"The Grand Ole Opry" changed the course of country music, bringing the music from the mountains and hollers to a nationwide audience through its weekly show. This archive of the radio program offers hundreds of hours of Opry radio programs from several decades of the show's existence.

A history of the radio jingle

As the radio became a fixture in American households, advertisers recognized the airwaves' commercial potential. Inspired by 19th-century commercially minded poems, the radio jingle was born in 1926 with the ditty "Have You Tried Wheaties?" This guide from the University of Maryland walks you through the evolution of the form, with recordings of its earliest earworms.

The first nationally broadcast soap opera was 'Clara, Lu, 'n Em'

The show first aired in Chicago in 1930, but was then picked up by NBC and broadcast across the country in 1931. The show followed three women who lived in the same duplex. Listen to a 1934 episode below, including the preshow's soap-centric advertising.