Electronic tremolo employs circuitry to mimic musical effects that have traditionally been produced by playing techniques on certain instruments. If you were ever required to memorise Italian terms for music theory exams, you may be familiar with the word tremolando , and there’s even notation for tremolo on musical scores. Tremolando from Italian translates as ‘trembling’ and can refer to fluctuations in volume, the fast repetition of a single note or rapid alternation between two notes.
A string player might achieve these effects by quickly moving a bow back and forth, and a balalaika, mandolin or guitar player may employ fast alternate picking using a plectrum . And we’re all familiar with the hammering on and pulling off that so many blues and rock players use to get that two-note trill. Church organs with tremolo started appearing as early as the 16th century.
It was mechanical, rather than electronic, and was produced by opening and closing diaphragms in the pipes to modulate air pressure. In addition to modulating volume, this also caused fluctuations in pitch. Tremolo arms notwithstanding, we tend to refer to pitch fluctuations as vibrato, rather than tremolo.
But there is a long tradition of using both terms interchangeably and maybe Leo Fender was attempting to distinguish his whammy bar system from Paul Bigsby ’s. Later, when Fender developed volume-modulating tremolo circuits, the company was almost obliged to describe the effect as vibrato. Electro-Mech.