Before revision: History As the terminology indicates, this originated and is particularly associated with a particular technological era, namely the mid-to-late 20th century, where magnetic tape and slide projectors were common, but digital audio (such as compact disks ) and digital projectors or video were not.
After revision: History As the terminology indicates, this originated and is particularly associated with a particular technological era, namely the mid-to-late 20th century, where magnetic tape and slide projectors were common, but digital audio (such as compact discs ) and digital projectors or video were not.