After World War II, commercial development of tape-recording blossomed following development of reel-to-reel tape machines by Ampex , Magnecord and other American manufacturers   In 1948 magnetic recording became the standard for mastering music phonograph recordings and in radio broadcasting. As tape recorders became more affordable, home tape-recording became popular in the early 1950s. Development of multiple channel tape-recording led to the stereo revolution in the late 1950s. Multi-track tape also revolutionized music by allowing instruments and performances to be recorded individually for later mixing into a final cut.  Small performance flaws could be easily corrected without re-recording the entire session with tape editing.

Magnetic tape brought about sweeping changes in both radio and the recording industry from 1950s to the 1980s when the digital computer revolution took over eventually making magnetic tape obsolete.    Sound could be recorded, erased and re-recorded on the same tape many times, sounds could be duplicated from tape to tape with only minor loss of quality, and recordings could now be very precisely edited by physically cutting the tape and rejoining it.
In the early 50s American musician-inventor Les Paul invented the first multi-track tape recorder, bringing about another technical revolution in the recording industry. Tape made possible the first sound recordings totally created by electronic means, opening the way to the innovative pop music recordings of artists such as Frank Zappa, The Beatles and The Beach Boys.

Tape enabled the radio industry for the first time to pre-record many sections of program content such as advertising, which formerly had to be presented live or on scratchy electrical transcriptions (ET's) (See "Electrical Transcriptions").  It also enabled the creation and duplication of complex, high-fidelity, long-duration recordings of entire programs and for the first time, allowed broadcasters, regulators and other interested parties to undertake comprehensive recording of radio broadcasts.

Cutting and splicing tape became the standard for editing content which required an abundance of patience and a knack for locating the right spots to cut and splice.   A cutting block, a razor blade and special bonding tape were the tools used to accomplish the task.     Cutting and splicing became the most precise way of editing magnetic tape,  however,  some editing could be done by a process calling "dubbing" use the tape recorder(s).    Click here for more information on magnetic tape

Editing Magnetic Tape
L-R   A splicing block was used to cut the tape while holding the tape in position to make the splice.  Today, editing is done digitally by computers and software programs.
L-R  Close up of a commercial grade tape recorder with the splice bar visible in the foreground.   -  Roll of magnetic tape threaded through the mechanism of a Studer tape recorder made in Germany.