History of Magnetic Recording Reading

The progress of sound and it's different component was highly influenced by research in the 18 and 19 century, including techniques such as electromagnetism ( using magnetic fields to produce the current that sound waves came from), magnetic recording theaory (a theory that detailed how iron fillings passing through a coil could create a magnetic signal that could then produce sound), and the telegraphone (a device which used hard steel to achieve a similar goal). All of these influenced the use of modern devices such as tape recording which came from the use of magnetic tape and wire. The enterance of computers however completely changed these ideas and created a whole new platform to record almost infinite amounts whereas previously very short clips were created. The use of magnetism is still very essential to the recording process however now it is done at a much smaller scale.
This article is slightly outdated but obviously the research and theories hold true, it's final section is just slightly behind in time.