In the mid to late 1880's, scientist Heinrich Hertz theorized and proved that electricity travels on electromagnetic waves (light). In this time, he conducted experiments sending and reciving these waves. This is were we get "hertz" from as a mesurment in sound and light waves.
The First Radios
Some of the first "radios" are what we would refer to as telegraphs today. They were wireless and found on ships most of the time. This reduced the feeling of icolation on ships and provided safety.
Wireless Energy - Telsa
Nikola Telsa invented a machine in the early 1890's that allowed electromagnetic energy to transfer wirelessly from one place to another. He publicly deminstrated this in 1893.
Marconi invented the more modern radio of today, but it still worked as a "wireless telegraph". It could sense the vibrations (waves) of a person's voice enough that it could transmit that message to another person.
The First Use
The first time Marconi's radio aperatus was used publicly was when a ship, The R.F. Matthews, sent a distress signal using the device. It worked so well for its time that they began installing them in ships everywhere.
The Trans-Atlantic Signal
Marconi became the father of radio when he did was he was told was impossible. He sucessfully transmitted a radio transmission from Ireland to Canada, across the Atlantic.
In 1906, Fesseden is the first person to take advantage of the radio and produced the world's first "radio program". He hosted a show with scripts, music, and interviews. For the time, it was un heard of, and amazing.
In 1906, DeForest created what he called the "Audion". This little tube compressed airwaves and amplified their signals. This allowed for radio to travel greater distances and reach more people.
Transmission From Above
Only seven years after the first maned flight, the first radio signal transmitted from an airplane happened in 1910. This proved helpful for pilots. They could now comunicate with people on the ground and greatly improve the system.
Federal Influence in Radio
In 1912, the American Government began to intervene in radio. They set regulations, and made it law that you had to have a permit to brodcast. You also had to have your own designated "channel" so you don't interfere with others.
Super Heterodyne Receiver
After WWI, engineer Edwin Armstrong of the USA patented this reciver based on reseach and experiments he conducted while in the army. After usage in the War, he only thought it fitting to present it to the public.
Vehicles With Radio
In 1921, Detroit police commissioner William Rutledge was the first public safety official to use a radio in his officer vehicle. It greatly changed how officers could communicate with one another and at headquaters. Eventually, regular cars were equipped with radios too.
In 1918, the Federal Radio Commission was established to bring order to the chaotic airwaves. Prior to the commission, ships, planes, and official vehicles were reciving a lot of interference. Afterwards, many problems were fixed.
In the late 1930s and early 1940s (WWII Era), many people back home were looking for anything to get the war off their minds. Many mucisians were playing their music on the radio, some even paying the stations to play their music more than other bands or people.
Rock & Roll is Born
In the early 1950's, right after WWII, white people began to imitate the black R&B genre and put their own spin on it. The result was popular and artists like Elvis Presley began to get a lot of airplay. Little did they know that this genre would become the most popular of all time.