Tremolo (accordion)
In the accordion, tremolo is an acoustically generated sound effect in which the amplitude and thus the volume of the musical signal is continuously modulated at short intervals .
origin
Also known as the musette tuning in France, as the introduction goes back to a French invention.
description
The effect arises when several reeds vibrate per tone, which have slightly different pitches.
The keynote series is tuned to the respective mood. Very often the equally tempered tuning or, with diatonic instruments, a tuning that approximates the pure tuning is used. Two or three reeds per tone can contribute to the generation of the floating tones (difference tones). If two tones are involved, the series of floating tones can be in tune above or below the fundamental tone, with three tones involved, one floating tone is tuned above and one below. Instruments with three reed plates involved have a fuller and more balanced sound; two different floating tones are not perceived, but rather a fuller, rounded tremolo. Instruments with two reed plates per tone have a clearer floating tone. If, for example, one tone is tuned to 440 Hz and the other to 443 Hz, the result is a superposition of the two tones, which is perceived as a volume fluctuation with a frequency of 3 Hz. With most instruments, the floating tones are in a range that can easily be determined by counting (estimating) the volume fluctuations per second. If there is very little beat, you can count over several seconds. But there are also modern tuners that can comfortably display several tones and generate curves over the entire tone range. Diagrams that show a representation of the tuning and the tremolo are only suitable for documentation, they are not necessary for the tuner.
variants
Depending on the strength of the beating, one speaks of flat, light, medium or strong beating. In the case of further gradations, the words “flat” or “strong” are followed by additions such as “very flat”, “somewhat flat”, “somewhat stronger”, “extremely strong” etc. No standardization is known. The stronger the beat, the louder and screaming the sound. With a strong tremolo, however, a considerable detuning occurs, which in turn is not perceived as clean by all people. French musette music uses accordions, which have a powerful tremolo, but there has been a recent trend towards flatter tremolos. Flat beats are much more difficult to tune than strong ones. The strength of the beat can also, or in most cases, be adjusted so that it is not the same over the entire tone range.
Since there are certain problems with both low notes and very high notes, these would have a negative impact on the sound. Depending on the strength of the tremolo, the lower tones are usually tuned with an increasingly lower tremolo and the higher tones with an increasingly stronger tremolo, with a more even course being preferred in the middle range. This leads to several possibilities: the curve can be S-shaped or ascending and linear, or there can even be a stepped variant.
Examples
Normally with a strong or flat beat:
| frequency | ||||
|---|---|---|---|---|
| Keynote | 220 Hz | 440 Hz | 880 Hz | 1760 Hz |
| Beat strong | 2 to 3 Hz | 4 to 5 Hz | 7 to 8 Hz | 11-12 Hz |
| Beat flat | 0.5 Hz | ... | ... | 2.5 to 3 Hz |
Notice and calculation
It should also be noted that values in cents are very misleading, as they say little about the strength of the tremolo. If the difference values between the two tones were kept in constant cent values per tone, a strongly progressive increase in the tremolo would result.
Even with cent values for the higher tone and the tone below the fundamental, there are slight differences with exactly the same beats for upper and lower tones.
