Rigidity
The hardness of the keys on a keyboard is the amount of resistance they provide when pressed.
—
Unweighted. Very low rigidity: the keys literally "fail" under the fingers. Found mostly in entry-level keyboards; this is due to the fact that unweighted mechanics are inexpensive, but the low pressure resistance makes it difficult to select the optimal pressure and control the dynamics of the sound.
— Semi-
weighted. Keyboards with medium resistance — not as high as on weighted keys, but noticeably higher than on unweighted ones. This option is considered optimal for active keyboards (see "Mechanics"): at a low cost, it gives quite good responsiveness and, with a minimum skill, allows you to accurately control the pressing force.
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Weighted. Keyboards with high resistance, which is comparable to the resistance of classical piano keys. Note that high effort in this case is an advantage: it allows you to bring the response of the keyboard as close as possible to the response of a classical piano and makes it easier to control the pressure and dynamics of the sound. Actually, by definition, all hammer-action models are made weighted (see "Mechanics"), but among active keyboards this option is rare — due to complexity and high cost.
Arpeggiator
The presence of an
arpeggiator in the keyboard.
The name of this function comes from "arpeggio" — a technique for playing chords, in which notes are not played all at once, but in turn. Accordingly, the arpeggiator is a function that allows you to play a taken chord in the arpeggio technique: the musician presses all the keys at once, and the keyboard plays them in turn. This effect can also be achieved manually, but in some cases the arpeggiator turns out to be more convenient: it plays notes at a clearly defined speed and interval, can accompany them with various effects, and provides other additional features. These features vary depending on the model, but some instruments allow you to create entire songs with the arpeggiator by simply pressing a sequence of chords.
Pads
The number of
pads provided in the design of the keyboard.
Pads are auxiliary controls in the form of characteristic pads, usually square. The pads respond to touch, each of them can be tied to a specific sound or even a sequence of sounds. One of the most popular ways to use pads is to play drums or other rhythmic instruments.
Faders
The number of
faders provided in the design of the keyboard.
A fader is a slider control. The simplest kind of such controls is the volume setting; if there is one fader in the design, most likely it is responsible for the volume. If there are more controls, other functions can be tied to them, respectively — in particular, changing the settings in the recording programme on the computer to which the keyboard is connected.