MIDI keyboard

MIDI controllers in this category have keys meant to resemble those of a grand piano, pipe organ, or synthesizer. Each of these action types is designed differently from the next, which, in turn, gives the action a particular "feel" to the player and lends it to an ideal usage.

• Synth action: un-weighted, often spring-loaded— ideal for music that calls for playing quickly, and may be favored by those with no piano or keyboard experience due to less required effort to depress the keys. Synth action is generally less expensive and weighs less than its weighted key counterpart.
• Semi-weighted action: similar to synth action, but with slightly increased resistance— also ideal for playing quickly, but allows for more dynamic playing on velocity-sensitive sound patches due to increased feedback from the keys
• Waterfall keys: semi-weighted keys with smoothed and rounded edges— meant for emulating organ keys (i.e. Hammond B-3 organ) and ideal for playing organ-specific techniques (i.e. palm glissando/smears)
• Hammer action: piano-style action with fully weighted keys— meant to provide resistance similar to an acoustic piano action and ideal for playing piano or electric piano instrument patches
  • Graded hammer action: hammer action with graded resistance— keys in the upper register are lighter than keys in the lower register, and resistance increases incrementally as one descends the keyboard from high to low, like an acoustic piano action (e.g. grand piano)
  • Graded hammer action with wood: graded hammer action with wooden key cores— the closest in realism to an acoustic piano action (as acoustic piano keys are made of wood)

Many examples of the above actions, other than the waterfall keys, will include a small lip that protrudes from the top of the distal end of the white keys. This is emulating a customary design detail found on acoustic piano keys. Keyboards with any type of hammer action are most likely to display this lip.

When a Musician presses a key three things can happen: How fast the key is pressed, is called "attack velocity', or after the key is pressed, it can be held down and pressed harder or softer, this is called 'key pressure' or sometimes 'channel pressure' if it affects all the keys on the keyboard, and how fast the key is released, is called 'release velocity'. Inexpensive keyboards have no velocity capabilities and thus produce the same volume and tone regardless of the velocity. More expensive keyboards have attack velocity. Professional keyboards often have both attack velocity and key pressure. Only a handful of exotic and expensive keyboards have release velocity. Unfortunately, every manufacturer refers to these three key abilities by different names, sometimes using proprietary terms. Some manufactures refer to 'key pressure' as 'aftertouch'.

Most of these traditional key keyboards determine the attack velocity, sustain, and release of a note based on a calculation made between two sensors in each key. Some high-end keyboards have triple sensors, claiming improved accuracy in the tracking of key movement, which could translate into a more detailed, and perhaps more expressive, performance.

Some MIDI keyboards are capable of sending aftertouch data, which can be assigned to a variety of effects, including: vibrato, pitch bends, and volume swells. Aftertouch data is generated when a key is depressed further into the keybed after its initial depression (without releasing the key). Keyboards can be equipped with channel or polyphonic aftertouch. The former sends only one aftertouch message, regardless of which key is depressed; the latter sends individual aftertouch messages for each key. Keyboards with every key aftertouch can enable the performer to create aftertouch effects on particular notes, such as emphasizing a melody note by continuing to press it.

Continuum Fingerboard.

While the vast majority of MIDI keyboards utilize variations on the traditional piano-style action, a few manufacturers make MIDI keyboards with a non-traditional action. One example is the Continuum Fingerboard, which is based on a "fretless" type keyboard interface, enabling portamento style note changes at will during play. Another unconventional MIDI keyboard is the Tonal Plexus keyboard, which provides for up to 1266 different pitches possible through the TPX6 1266 Keys (Microtonal MIDI Controller).

The ROLI Seaboard line of MIDI keyboards has soft, squishy keys, that have a foam rubber-like texture. This allows performers to play notes that fall "in between" the normal 12 notes of the Western chromatic scale, similar to the way blues guitar players perform "blue notes".

All the above-mentioned MIDI keyboards use aftertouch to create new performance capabilities. For instance, the Roli Seaboards can sense left-to-right, front-to-back, downward pressure/depth, and the rate of change in each of these parameters. All that information can then be used to control the behavior of a digital instrument or synthesizer.

• 25-key: generally the smallest MIDI keyboard available— portable and light, but only suitable for playing one-handed piano parts such as basslines.
• 49-key: considered the smallest MIDI keyboard size upon which to play two-handed piano parts effectively.
• 61-key: ideal size for playing two-handed piano parts— same key count as a single manual from a classic organ like the Hammond B-3.
• 88-key: full key range— same key count as an acoustic piano— the "gold standard" when playing piano and electric piano, but least portable and heaviest of the MIDI keyboards.

Piano de Voyage collapsible MIDI keyboard

• 32 & 37-key: compared to 49-key keyboards, these are more compact and easy to carry. Compared with a 25-key keyboard, they offer a greater range
• 64-key: Roland has a 64 keys hammer-action keyboard (RD64 [1]) which is more compact than regular 88-keys
• 73 & 76-key: compared to 88-key keyboards, these are more compact and easy to carry. Compared with a 61-key keyboard, they offer a greater range
• modular some small manufacturers are making collapsible keyboards (Kombos,[2] Piano de Voyage[3]), made of sections of 1 to 2 octaves. These keyboards are focused on portability

Most 25-key through 49-key keyboards come equipped with synth or semi-weighted actions. Most 49-key and 61-key keyboards come equipped with semi-weighted actions, but some may be found with hammer actions. Waterfall keys can be found occasionally on some 61-key and 73-key keyboards. Most 73-key through 88-key keyboards come equipped with hammer actions; however, some may be outfitted with semi-weighted actions.

MIDI keyboards are usually full-size keys, like a grand piano. Some smaller keyboards use minikeys, which are smaller. Some tiny keyboards have flat minikeys which are even smaller.