Mechanics
Type of action used in synthesizer keys.
— Passive. The simplest type of mechanics, when each key is, in fact, a “switch” for its note: it only turns the sound on and off, while the volume of this sound does not depend on the strength and intensity of pressing. Passive keyboards usually have unweighted, less often semi-weighted hardness (see below). Their main and, perhaps, the only advantage is their low cost, due to the simplicity of design. At the same time, the capabilities of such tools are very limited, and even when training, it is recommended to use them only at the very initial stages. As a result, passive mechanics are used exclusively in the simplest low-cost-level synthesizers, which are more suitable for the role of a toy for entertainment, rather than a full-fledged instrument.
— Active. A mechanic that provides a relationship between volume and pressing force: the harder the key is pressed, the louder and sharper the sound will be. Most often combined with semi-weighted, occasionally unweighted hardness (see below). Such keys already make it possible to control the dynamics of each note: select its volume "on the fly", highlight accents, use special techniques, etc. This feature is especially important in training, when you need to train to control the effort on each individual finger.
Active mechanics are highly recommended even for an inexpensive synthesizer, and for a mid-range instrument it is almost
...mandatory, as well as for serious learning. At the same time, many models may provide sensitivity adjustment, or even a complete switch to passive mode (for example, to simulate some instruments).
— Hammerhead. The most advanced kind of mechanics. Like the active one, it provides volume control depending on the force of pressing, but it fundamentally differs in response: hammer action is used only in weighted keyboards (see "Rigidity"), and the feeling when playing it is close to playing on a real piano. The degree of approximation, however, can be different — some models are indistinguishable in sensations from the piano, in others the mechanics are simpler. However, anyway, such features are not cheap, despite the fact that the real need for a "piano" response is extremely rare. As a result, hammer action keyboards are found mainly among top-class instruments, mainly workstations (see "Type") with full-size keyboards for 88 keys.Built-in timbres
The number of built-in sounds provided in the synthesizer.
The number of timbres is often described as the number of instruments that a given model can imitate. However, this is not entirely true — rather, this parameter can be called "the number of instruments and sound effects." For example, the same instrument — an electric guitar — with different "gadgets" (distortion, overdrive) will sound differently, and in the synthesizer each such gadget will be considered a separate timbre. The “drums” timbre usually combines different types of drums and other percussion instruments — in other words, it allows you to portray both the “bass drum” and the cymbals without switching settings, just by pressing the desired keys. And some timbres may not have analogues among real instruments at all.
The more built-in timbres, the more extensive the possibilities of the synthesizer, the more diverse the sounds that can be extracted from it. At the same time, in high-end models like workstations (see "Type"), this number can reach 1000 or even more.
Auto accompaniment
The presence of the auto accompaniment function in the synthesizer.
This function allows the instrument to automatically play an accompaniment melody that you can play along with the main part on the keyboard. At the same time, the left hand of the musician can control the accompaniment: it is enough to take a chord on the left half of the keyboard, and the auto accompaniment will automatically “decompose” it into instrument parts that sound in accompaniment. Thus, the musician turns into a "man-orchestra": one synthesizer can replace the whole ensemble, or at least a solid part of the ensemble. Of course, the sound quality in such models can be different, and not every synthesizer with accompaniment is suitable for an event more serious than a children's party, although there are quite advanced models.
In addition, playing to accompaniment can also be useful for educational purposes: it contributes to the development of general technique, a sense of rhythm, and additional accompaniment is very convenient during improvisation exercises.
It should be taken into account that not only the sound quality, but also the number of accompaniment styles (melodies) can be different; and some models allow you to record your own melodies. See below for more details on these features.
Accompaniment styles
The number of auto accompaniment styles (see above) originally provided in the synthesizer, in other words, the number of accompaniment options available to the user.
The more extensive this set, the higher the probability of finding among these melodies suitable options for a particular case. At the same time, the abundance of styles in itself is not yet a 100% guarantee that among them there will be a suitable one, especially since different synthesizer models can differ markedly in a specific set of melodies. So the list does not hurt to clarify before buying. Also note that the situation can be corrected by user styles (see below) — many synthesizers with auto accompaniment support them.
Tempo change
The range in which you can change the tempo of the programme played by the synthesizer — auto accompaniment, lesson tune (see above), metronome (see below), recorded sample, etc.
Pace is measured in beats per minute. Changing it allows you to adjust the speed of the synthesizer to the specifics of the situation — for example, slightly slow down the tutorial if it is too hard to master at the initial pace. The wider the range of tempo adjustment, the more options the musician has to choose from, especially in the area of very slow and very fast tempos.
Note that the traditional range of musical tempos covers values from 40 beats / min (“grave”, “very slowly”) to 208 beats / min (“prestissimo”, “very fast”), however, in synthesizers it can be more extensive — for example, 30 – 255 bpm.
Metronome
The presence of a built-in metronome in the design of the synthesizer.
A metronome is a device that produces sharp sound signals (beats) at certain short intervals specified by the user. In music, such a device is used primarily to maintain a given tempo. A metronome can be useful both for a beginner musician, for developing a sense of rhythm, and for a professional, for example, when learning a new melody, especially if it is to be played without accompaniment and you will need to maintain the rhythm yourself. In addition, the sound of the metronome can also be used as an effect in musical compositions.
Mixer
The presence of a mixer in the design of the synthesizer.
A mixer in this case is a device designed to control individual audio channels that make up the sound of a synthesizer as a whole. The list of these channels includes, in particular, the main voice, the layered voice (see “Dubbing voices”), several auto accompaniment channels (main, bass, drums, etc.). With a mixer, the musician can manually control these channels — turn some of them on and off, switch the timbre, tempo, key, etc. This greatly expands the possibilities for using the synthesizer.
Built-in compositions
The presence of built-in compositions in the design of the synthesizer.
This function is similar to the auto accompaniment described above — in the sense that it involves playing songs on the synthesizer itself. However, unlike Auto Accompaniment, Preset Songs play strictly by note and cannot be controlled using chords on the left half of the keyboard. In other words, with auto accompaniment, the musician has a lot of freedom, and you have to play along with melodies in strict accordance with it.
Built-in compositions can be used for a variety of purposes. One of the options is training: the musician listens to a reference recording and then tries to reproduce it, either plays along with the melodies according to the given notes, or improvises to it. In addition, in some cases (for example, at mass events), the ability to turn on the synthesizer as a player can be very useful. Also, built-in songs are used to test and demonstrate the general capabilities of the instrument: it is assumed that the recorded song can be repeated using the synthesizer itself.
Keyboard split
Possibility
of dividing the keyboard of the synthesizer into two parts, each of which is responsible for its own timbre of sound. Thus, on one keyboard, you can play two "instruments" at once in real time — for example, accompany the solo part of the violin with chords of a string orchestra. At the same time, unlike auto accompaniment (see above), all notes are taken by the musician himself, without relying on the automatic settings prescribed in the programme.
Usually, several “split keyboard” combinations are pre-written in the synthesizer’s memory, however, some models allow you to separately select a timbre for each half, at the discretion of the musician.