why songs are not considered as audio visual sorce of history? simply,if we have a option between photographs,songs and recordings; which of these are not an example of audio visual source of history?
Answers
The history of sound recording - which has progressed in waves, driven by the invention and commercial introduction of new technologies — can be roughly divided into four main periods:
the "Acoustic" era, 1877 to 1925
the "Electrical" era, 1925 to 1945
the "Magnetic" era, 1945 to 1975
the "Digital" era, 1975 to the present day.
Experiments of capturing sound on a recording medium for preservation and reproduction began in earnest during the Industrial Revolution of the 1800s. Many pioneering attempts to record and reproduce sound were made during the latter half of the 19th century – notably Scott's phonautograph of 1857 – and these efforts culminated in the invention of the phonograph by Thomas Edison in 1877. Digital recording emerged in the late 20th century and has since flourished with the popularity of digital music and online streaming services.