There is no simple date or invention that can be pointed to as the beginning of the electrical era of audio reproduction. Like early sound reproduction the process was an uncoordinated mess of competing interests and lucky breaks. However, it is possible to point to one thing that all of these inventions had in common: they depended on the discoveries of James Maxwell and Michael Faraday, which showed that electricity (the flow of electrons) could be reliably manipulated through the strategic placement of magnets, and capacitive plates (Cook, 2002).
Our analysis of audio production in the electrical era will be focused on understanding how the manipulation of electro-magnetism influenced the types of inventions, which in turn changed the way the process of recording took place. As such, the three most fundamental shifts in recording technique were the inventions of the electric microphone, the triode, and magnetic tape.
In the physical era of sound reproduction the fidelity of a recording to its source depended on the ability of the performer or performers to work within or around the stringent limitations of the phonograph. In practice this often meant that certain types of performances (large bands, orchestras) were practically impossible, or at least very difficult. Horns, brass or wood, suffered from all kinds of sonic artifacts, like unwanted resonances and problems of acoustic isolation (Welch and Burt, 1994).
The microphone, especially the ribbon microphone, changed all of this. By transducing the sound waves in the air into analogous oscillations in an electric current, an incredible range of new techniques and sounds could be recorded. For instance, no longer would musicians be limited by the physical constraints of having to be close to the phonograph’s cone. In fact, by running a cable from the microphone to the recording apparatus, and powering the circuit through pre-amplification, a sufficient audio signal could be captured from many, many meters away.
Despite the improvements the electric microphone offered recording, it was still limited in an important way. The current in the circuit, typically measured in volts, had to be set prior to the recording. In practice this meant that if you were recording a particularly quiet piece, you had to pre-amplify the circuit to run at a higher current. But if something loud were to happen, it would overload the circuit, causing the audio to clip and distort. However, setting the gain high wasn’t perfect either, as a higher current creates more thermal energy which manifests itself as an audible 'hum' at the low or high end in a recording. A similar problem happened in the physical era, but the noise was made by the needle scrapping the recording medium, or by the mechanical operation of the machine itself (Sterne, 2003).
The invention of the triode, a modification on the diode (a tube with a positive and negatively charged end) by Lee de Forester helped ameliorate this problem. By allowing for the live amplification of an electric current, through the manipulation of the voltage in a third node commonly called a grid, the electric signal could be increased or decreased. This allowed for the full complexity of a piece to be more accurately captured without any of the lingering signal to noise artifacts of a pre-amplified recording, gone were the complex studios full of movable stools and pulleys, now studios had large padded rooms with massive electric generators to power the recording equipment. Moreover, triodes allowed for signals to be picked up, and amplified in personal radios. Previously radio receiveing stations required fixed and relatively large generators in order to percieve anything. Triodes, allowed for the signals captured by your radio antenna to be amplified at the twist of a knob i.e. volume (Sarkar, 2006).
However, arguably the most significant change and improvement in audio recording during the electrical era was the invention of magnetic tape by Fritz Pfleumer. Unlike the microphone and the triode which were changes on the recording end, the invention of magnetic tape was a change in both the process of recording and the physical medium itself.
In the Physical era, sound recording relied on the same basic principles as that of the human ear, and phonautograph i.e. the sound of your voice transferred to the vibrations in a diaphragm, transfered to grooves in some medium. Even with the advent of the electric microphone, the recording process remained mostly the same i.e. the sound in your voice was converted to an electric signal, which was then converted into vibrations in a diaphragm, and then grooves in a record. Magnetic tape was totally different, instead of physical grooves, it encoded soundwaves into the orientation of magnetic particles on a strip of celluloid tape. Sound, which had previously been transmitted electrically, was now also stored electrically.
Bing Crosby, the famous radio artist, was one of the first to recognize tapes recording potential. Because it was thin and its information stored linearly, as opposed to the spiral of a relatively thick plastic disc, it was possible to record specific sections of audio, and cut them, much like film, splicing them into other sections. Crosby was one of the first to do this, specifically, by adding-in sections of laughter and applause — the origins of the sitcom laugh track (The New Yorker: How Bing Crosby and Nazi’s Helped…Silicon Valley). In addition to its flexibility as a recording medium which allowed for unprecedented control over the recording process, it also provided an increased frequency and dynamic range bandwidth, since the limitations of the ‘stylus’ and the ‘wax’ were no longer important.
The cultural analysis of audio fidelity, situated in the broader topic of mechanical reproduction, particularly, though not exclusively in the electric era, tends to fixate on how the rise of increasingly manipulative recording techniques, in cinema, or music, resulted in the ‘decline’ of the uniquely ephemeral aspect of human performances. For Benjamin, the rise of film resulted in the destruction of the ‘aura’ associated with the dynamic relationship between an audience and performer. Likewise, for Adorno, the decline of the “live” performance and rise of recording technologies made music “absorb into itself” and in doing so, abandon its “height and abyss” (Adorno, 1990). What both of these critiques argue is that something essential, the "productive force" for Adorno, and the "aura" for Benjamin, dies in the groove. It becomes a historical artifact, a text to be consumed and interpreted, rather than experienced (Adorno, 1990).These theoretical suppositions are problematic for many, many reasons (Sterne, 2003). However, for our purposes, the biggest problem is that they largely ignore the possibility that different “heights and abyses” can emerge from how we relate to new technologies. For instance, thematically, what difference is there in the imaginary space between the play macbeth and the film macbeth? Doesn't the ‘aura’ emanating from Ian McKlellan appeal to a similar imaginary space as Michael Fassbender? Taken thematically nothing novel is happening in mechanical remediation: the essential emotions, desires, and narrative remain fundamentally human; the technology may changes the means by which we relate, but it does not change the relationship itself.