Aftertouch
The presence of the aftertouch function in the keyboard (aftertouch). The essence of this function is to track the pressure force on the key after it is pressed. In fact, this means that in models with aftertouch, you can control the sound not only due to the force and speed of pressing the key, but also due to the change in pressure on it after pressing; this gives additional features and allows you to use various specific tricks of the game. The specific ways of changing the sound “tied” to aftertouch can be different, depending on the synthesis settings set: for example, when recording a guitar part, you can tie a small change in tone to this function and imitate string bending, when recording a saxophone, change the volume of notes, and etc.
Relatively inexpensive models use a common sensor to monitor aftertouch, which monitors the average force of pressure on all keys pressed; in more advanced ones, separate sensors are installed for each key.
Regulators (encoders)
The number
of encoder controlsprovided in the design of the keyboard.
Such a knob looks like a rotary knob, with which you can control various functions of the device to which the keyboard is connected — for example, turn the virtual knobs in the programme for recording and sound processing. At the same time, we note that a full-fledged encoder is capable of rotating 360 ° and turning to any angle in any direction, however, keyboards can also contain knobs with a limited rotation sector — they can also be called encoders. None of these options has a clear advantage: in some cases, an unlimited turning sector is more convenient, in others, a limited one.
MIDI out
A specialized output for transmitting MIDI signals to an external device — a sequencer, a computer sound card (if there is a MIDI In input), etc.
MIDI signals are a kind of "digital notation": they tell which key was pressed, with what force and for how long, and also carry information about various additional parameters: timbre, tempo, key, etc. To convert such signals a "ready" sound requires an external sequencer (software or hardware).
Note that despite its specialized purpose, the
MIDI Out output is not mandatory for modern MIDI keyboards: MIDI signals can also be transmitted via other interfaces, such as USB or Bluetooth (see the relevant paragraphs). So it makes sense to specifically look for a keyboard with such a connector if you plan to connect it to equipment with a MIDI In input.
Display
The type
of display that the keyboard is equipped with.
Most modern MIDI keyboards have relatively simple monochrome (single colour) displays. Such screens are inexpensive, and their capabilities are sufficient for most cases. However, there are also models with colour screens — usually, such equipment is a sign of an advanced keyboard with an abundance of additional functions; for simpler devices, a colour display is overkill.
