The Tremolo effect

Tremolo is a highly versatile sound effect that has become a staple in music. Its use has spanned centuries thanks to adaptations and the creativity of musicians. By modulating volume in a cyclic and rhythmic manner, it imparts an unparalleled depth and dynamism to instruments.

What is Tremolo?

Tremolo is an audio modulation effect commonly used with electric guitars like the chorus or the phaser. It rhythmically and consistently increases and decreases the volume of the instrument’s sound. Amplitude modulation effects vary the volume of the source signal. If we had to describe the tremolo effect, we could say that it produces a kind of sound that makes the notes go back and forth!

Tremolo is neither a delay nor a vibrato. It is the volume drops of the instrument that generate a pulse and a sensation of persistent and dynamic rhythm. Tremolo is often confused with vibrato. Tremolo acts on the volume, while vibrato acts on the pitch of the signal.

Origins of Tremolo

Tremolo, characterized by rhythmic variations in volume, has been a technique employed by musicians for centuries. The desire to emulate the natural tremolo effect produced by the human voice and certain instruments, such as the violin, spurred the development of tremolo mechanisms. This is a classic effect for a bowed string player. Tremolo is learned from a very young age. On the violin, cello and viola, it consists of creating a monophonic effect of variation in volume from a single note by applying more or less pressure on the strings using the bow. The tremolo technique exists for many instruments (guitar, piano, trumpet, harmonica and many others). Its production differs from one musical instrument to another because they have different structures.

The first electronic tremolo device is attributed to DeArmond, who introduced a unique tremolo system initially designed for pianos rather than guitars. This tremolo mechanism utilized a metal box containing a jar filled with an electrolytic fluid, which was agitated by a motor. The speed of the motor, controlled by a knob, regulated the fluid’s movement, producing the tremolo effect.

Tremolo’s appeal extended to guitarists, prompting amplifier manufacturers to incorporate tremolo circuits directly into their amplifiers. These tremolo-equipped amplifiers graced the stages of blues, country, and surf music genres. Numerous manufacturers offered their tremolo-equipped amplifier models, with the Fender Tremolux and Gibson GA-50T standing among the most celebrated.

Notable Tremolo Usage

Tremolo has found its way into the music of various bands and artists across diverse eras and genres. Its prominence was particularly evident in the 1950s and 1960s, gracing blues, surf music, rock, and country genres. Tremolo later experienced a resurgence in the newer rock genres of the 1990s.

Additional notable tremolo usage includes The Rolling Stones’ Gimme Shelter and The Smiths’ How Soon Is Now? Tremolo’s rich history and versatility have made it an enduring effect in various musical landscapes, adding depth and expression to countless performances. Below are three video examples showcasing tremolo usage by Otis Redding, Dick Dale, and Tommy James and the Shondells.

Differentiating Tremolo Effects

Harmonic Tremolo vs. Standard Tremolo

Harmonic tremolo emerged in the 1960s through Fender amplifiers. The brand gradually shifted away from their early delay-based amplifiers and embraced other amplifiers incorporating different controls, including harmonic tremolo. As mentioned earlier, a standard tremolo varies the volume of the input signal. Harmonic tremolo, on the other hand, alternates between the bass and treble frequencies of a signal using filtering circuits. The harmonic tremolo effect produces a warmer sound compared to a standard tremolo.

Tremolo vs. Vibrato

Tremolo and vibrato are often confused by guitarists. It’s worth noting that the marketing of amplifier and pedal manufacturers has not helped to clarify the distinction between these two effects. They have historically mixed the two terms, even going so far as to call a tremolo a vibrato to differentiate themselves. Not to mention that Leo Fender called the whammy bar on his Stratocaster a tremolo, when it actually produces a glissando effect, a musical technique that rapidly transitions between different pitches. In short, it’s a bit of a mess!

To understand the difference between a tremolo and a vibrato, the simplest way is to observe how a violinist produces these two common effects on a violin.

Remember that: vibrato is a modulation of the height of the signal (pitch), while tremolo is a modulation of the volume of the signal.

How to Use and Set Up a Tremolo

Tremolo Pedal Settings

Most tremolo pedals have two main controls:

• Depth: Sets the intensity of the tremolo modulation.
• Rate: Controls the speed of the tremolo. The higher the rate, the more prominent the cyclic repetition of the tremolo effect.

Some pedals also offer a ‘Wave‘ control that determines the waveform, ranging from triangular to square. The smoother the waveform, the smoother and more harmonious the tremolo effect. The more abrupt and square the waveform, the more aggressive the tremolo effect.

Where to Place a Tremolo on a Pedalboard?

Like most modulation effects, a tremolo is typically placed between overdrive/distortion pedals and time-based effects like delay and reverb. So, it should be after an overdrive but before a delay. Some musicians prefer to place modulation effects in the effects loop of their amplifier using the 4-cable method. However, it is entirely possible to position it elsewhere to obtain a different style!

Using Tremolo in Music Production

Tremolo is often used on slow guitars to give them a richer sound and add presence to each note. A simple chord can gain a more impressive presence with tremolo. In the 1960s, tremolo was commonly used throughout a song to enhance the sound of a guitar. However, this overused approach has become somewhat outdated.

After a period of relative decline, tremolo made a comeback in the 1990s, often used sparingly to add a temporary textural element to guitar riffs. A well-known example is the introduction to Rage Against the Machine’s Guerrilla Radio, where guitarist Tom Morello, a renowned effects enthusiast, revived forgotten effects to create his signature sound. Tremolo also graced several Radiohead tracks, such as the intro to Bones. Without forgetting the guitar riff from Boulevard of Broken Dreams by Green Day which remains audible throughout the entire track, even if it is drowned out in the general mix!

Tremolo Pedal Recommendations

Each manufacturer has its own tremolo model, typically featuring the control options mentioned earlier. Here are a few highly regarded tremolo pedals:

• Nano Pulsar Tremolo by Electro-Harmonix
• TR-2 by Boss
• Pipeline Tap Tremolo by tc electronic (the more affordable Choka Tremolo is also an excellent choice)
• Flint V2 by Strymon (combines tremolo and reverb, two closely related effects that were often paired on older amp models)
• Monumental Tremolo by Walrus Audio (offers both standard and harmonic tremolo)

Choosing among these five pedals is a tough task, as they are all fantastic options! Ultimately, your budget will play a significant role in your decision, as these pedals vary considerably in price and features.

Tremolo VST Plugin Recommendations

Numerous tremolo VST plugins are available for DAWs. Here are four notable options:

• Adam Monroe’s Tremolo by Adam Monroe (free)
• Tremolator by Soundtoys
• Trem Control by Goodhertz
• Efektor TR3604 by Kuassa

Tremolo is an expressive tool that has transcended musical genres and generations of composers and musicians. From its bold beginnings with rudimentary technology to today’s devices, tremolo has been adapted by its users with the same goal: to enrich musical compositions. Incorporating a tremolo into your sonic arsenal opens up creative horizons!