The birth of public radio broadcasting is credited to Lee de Forest who transmitted the world’s first public broadcast in New York City on January 13, 1910.
Photograph of a February 24, 1910 radio broadcast, from Lee de Forest's laboratory in New York City, by Mme. Mariette Mazarin of the Manhattan Opera Company. From "A Review of Radio" by Lee DeForest, page 333 of the August, 1922 issue of Radio Broadcast.
- wikimedia.org
A 1907 Lee De Forest company advertisement said:
It will soon be possible to distribute grand opera music from transmitters placed on the stage of the Metropolitan Opera House by a Radio Telephone station on the roof to almost any dwelling in Greater New York and vicinity ... The same applies to large cities. Church music, lectures, etc., can be spread abroad by the Radio Telephone.
However in 1932 Reginald Fessenden reported that as early as late 1906, he was the first person to conduct a radio broadcast of entertainment and music, although a lack of verifiable details has led to some doubts about this claim - see first entertainment radio broadcast.
But these Initial broadcasting experiments showed that the idea was not yet technically feasible, and neither de Forest, or Fessenden would not make any additional entertainment broadcasts until late 1916, when more capable vacuum-tube equipment became available.
In the meantime, on 15 June 1920 the first live radio recital by a professional musician took place at the Chelmsford factory, by the legendary Australian diva, Dame Nellie Melba.
This marked the beginning of what would become nearly universal wireless radio communication - wikipedia 
# First Public Radio Broadcast Several years later, on January 13, 1910, the first public radio broadcast was an experimental transmission of a live Metropolitan Opera House (39th St) performance by several famous opera singers.
This broadcast featured the voices of Enrico Caruso and other Metropolitan Opera stars. Members of the public and the press used earphones to listen to the broadcast in several locations throughout the city.
1910 The New York Times advertisement for the wireless radio - wikimedia.org
The New York Times reported on January 14, 1910:Opera broadcast in part from the stage of the New York City Metropolitan Opera Company was heard on January 13, 1910, when Enrico Caruso and Emmy Destinn sang arias from Cavalleria Rusticana and I Pagliacci, which were "trapped and magnified by the dictograph directly from the stage and borne by wireless Hertzian waves over the turbulent waters of the sea to transcontinental and coastwise ships and over the mountainous peaks and undulating valleys of the country.
The microphone was connected by telephone wire to the laboratory of Dr. Lee De Forest.
# See also * First public broadcast * Equipment - Early music transmission