The term "keyboard" covers a wide range of products from very basic MIDI (Musical Instrument Digital Interface) controllers to highly advanced workstations. They come in all shapes and sizes from little boxes to huge pieces of furniture. The number of keys varies substantially over different types of instruments.
To a beginner, all types of keyboards appear the same with groupings of white and black keys. However, each type of instrument is different in feel, size, weight, cost and may even be played differently.
In my article on "Types of Pianos", I had talked about Acoustic Pianos and Electro-Mechanical Keyboards in detail. Before delving into the types of electronic keyboards, I want to introduce you to some very common features that most modern keyboards have. This will help you in appreciating the differences between various types of keyboards.
If you want to buy your first keyboard, this article, along with our articles “Electronic Keyboards - Types and Functions” and "Tips on Buying your First Keyboard" will provide all the information that you are looking for.
Electronic musical instruments do not have any vibrating strings, hammers or spinning elements like their acoustic counterparts. They produce their sounds completely by electronic or digital methods through use of tubes, resistors, chips and circuit boards.
Common Keyboard Features
Before I dive into the different types of electronic keyboards, let me introduce you to keyboard features, which are most desirable in the keyboards:
Number of Keys:
The number of keys on any electronic keyboard can range from 25 to 88 keys. The important considerations to decide on the number of keys is the type of music you want to play, the range required, the space considerations and the portability of the instrument.
While the physical appearance of the keys on any instrument is more or less the same, there can be a big difference in the key mechanism or the way they play. First distinction is whether the keys are weighted, semi-weighted or unweighted.
Weighted Keys mimic the action of and gives the feel of playing an acoustic piano. The very action of pressing a key on an acoustic piano results in movement of many mechanical parts, eventually resulting in a hammer hitting a string to produce a note.
The lever mechanism causing hammer action has a natural resistance which feels like weight against which you have to push to play a note.The keys for high-end instruments are made of wood with a coating on top, making them much heavier than simple plastic keys.
While the weighted keys may appear harder to play they give you appreciable control over the dynamics, which is the ability to play loud or soft. With practice, you will learn how hard you need to press to get the desired sound. With adequate practice, you will develop sufficient finger strength to be able to play weighted keys for desired intervals of time.
Weighted keys can have graded weighting or hammer action.The keys are said to be having graded weighting when keys in the lower range have more weight than the higher range ones. So, lower range keys require heavier touch while playing. A digital piano has hammer action when it utilizes some sort of lever mechanism to replicate the hammer action of acoustic piano.
Semi - weighted and Unweighted Keys
Most of the keyboards above the beginner range have semi weighted keys. They are middle ground between weighted and unweighted keys. In this type, the resistance is provided by the spring action. Some manufacturers glue a metal bar to the underside of the key to increase its weight and give the feeling of solid touch. Hence, the quality can vary substantially between brands and models. Semi-weighted keys are firm, more solid light touch keys.
Weighted and semi-weighted keys increase the weight of the keyboard and make them costlier. So you need to consider your budget and portability requirements before deciding finally on these types.
Unweighted keys are also often known as synth-action keys. They are very light to touch and play. Most of the beginner and MIDI keyboards have unweighted keys. They are usually preferred by non-pianists for playing organs and synths.
Touch or Velocity Sensitivity
In musical terms, “Dynamics” refers to the changes in volume or loudness. Key actions are usually of two types - Dynamic and Non-dynamic. Dynamic key action includes touch sensitivity or velocity sensitivity. Dynamics can be created by use of foot pedals or by varying the touch of your fingers.
We may define touch or velocity sensitivity of any instrument as its ability to judge the magnitude of force or velocity, with which the player has pressed the key and to produce a sound proportional to this force or velocity. Actually, the energy from playing is transferred to the sound producing mechanism resulting in volume levels that may vary from soft to loud.
Non-dynamic keys are just like on / off switches that just produce the sound.
In Velocity sensitive instruments, the keys have two sensors, at the bottom and at the top of the key. Usually one sensor senses the rest position of the key. When the key is fully pressed, the other sensor picks its position. With the help of these two sensors, the system is able to measure the speed of the key and converts the speed signal to corresponding dynamic level.
While the terms touch and velocity sensitivity are both commonly used, velocity sensitivity is technically the correct term, based on actual principles of operation.
Electronic Keyboards can do much more than just playing sounds. They are loaded with a multitude of features and capabilities to astonish you. Very primitive appearing instrument can have dozens of groupings of sound. Most keyboards have hundreds and high end ones may have thousands of sounds. These may be simple single sound or those of combinations of instruments
Poly means “many” and phony means “voices”, so polyphony in musical parlance may be described as many notes or keys playing at the same time. On a guitar with six strings, we can play one note per string, so it is often termed as six note polyphonic. In contrast, the human voice is monophonic.
Unlike guitar analogy, polyphonic ability for keyboards is defined by the electronic circuitry inside, instead of the number of keys. Many analog synthesizers, particularly inexpensive ones, may be monophonic due to costs involved. But, almost all electronic keyboards have polyphonic ability of 32 to 256 notes. These several notes are created by the combination of oscillators, filters and amplifiers.
In situations where more notes than polyphonic capability of the instrument are played simultaneously, the algorithm may suspend the oldest notes from playing.
However, some of the instruments may utilize two notes to produce stereo sound as a preset. In this case, the polyphony is reduced to half of its value in the specs. Same is applicable for drum rhythms and auto-accompaniment patterns.
Multitimbrality is defined as the ability of the instruments to produce more than one type of sound, also known as timbre, at any given time. An instrument may be defined as 16-part multitimbral, which implies that it can produce 16 different sounds simultaneously.
One part may be piano sound, other may be flute and so on. Each part is assigned to an independent MIDI channel for individual control. Multitimbrality and polyphony are different things and should not be mixed.
As an example, if an instrument is designated as 16-part multitimbral with 64 note polyphony, these 64 notes can be played at once over the 16 parts or channels.
These days instruments are available with large polyphonic and multi-timbral capabilities, that they can mimic an entire orchestra.
In the vast majority of the cases, sound from the keyboards includes sonic treatment. This is called adding effects to the sound. The common sound treatments include reverb, chorus, delay, fuzz etc. You can vary the settings of these effects to get different results.
MIDI is an acronym for Musical Instrument Digital Interface standard. This is a communication protocol (established in 1980) which defines the way in which different electronic musical instruments / products and computers can talk to each other.
It does not contain any sound but is like a message which when tells the keyboard to play a specific note with particular velocity. Instruments can play it with any of the available or selected sounds.
MIDI compatibility refers to the ability of an instrument to send or receive MIDI messages.
With the development of the MIDI communication protocol, it became possible to connect the keyboards to the computers or tablets for communication. Today, these connections can even be done through the use of USB, mLAN, S/PDIF, FireWire or other types of interface technologies. As a minimum, most keyboards have USB or MIDI host ports.
These connections allow you to
Automatic Playing Features
Many keyboards now include functions to play on their own, based on your selections, while you sit back and listen. Some of the most common features are:
Many high end digital pianos and almost all arrangers and portables include the feature of automatically playing drum rhythms. These are also called drum grooves or drum styles. You can use the rhythm or styles button on the front panel to select the specific pattern you want or add some transitions known as fills. Synths and workstations may have these features set behind their sounds or the arpeggiator feature.
Many portable, arranger and high - end keyboards have the ability to play like a full band accompanying you. In most cases, playing some notes in lower range triggers the system to play the backing music from the selected style. The feature uses collections of MIDI based tracks to play various instrument sounds, recorded by skilled musicians.
Adaptability to the music being played is what makes this feature unique as against pre-recorded tracks. Accompaniment pattern has elements of drums, percussion, bass, chordal parts, other sustained parts and background melodic figures.
The literal dictionary meaning of the word Arpeggiation is to spread out a chord, instead of playing the notes in simultaneous fashion. This amounts to playing the notes of a chord in broken fashion, one at a time.
With this function, if you hold a few notes of a chord, the keyboard will play them in complex and varying patterns with repetitions to produce fancy riffs. The feature became popular in mid-’80s particularly in pop and dance music.
Harp flourishes, realistic guitar strumming and drum grooves are some of the advanced options of the feature.
Recording, editing, Sequencing and Sampling
Nowadays, many keyboards can perform very advanced functions, which only computers did in the past. Cost of internal memory devices was primarily to blame for the lack of these features. Let us dive deeper into the recording, editing and related functions
Virtual Recording Studio
Most keyboards include some form of recording so that you may play back and listen to your own performance. The recordings are of two types:
- 1Audio Recording - Actual sound played by you is recorded. It is possible to play these types of files in any common media player or transfer / upload to CD, computer, cloud service.
- 2MIDI Recording - In this type, you are basically recording your performance data and not the actual sound.The data includes what notes you are playing, when and how loud you are playing them etc. You can check out these recordings in the video below.
Shaping the sounds or Editing
Modern keyboards allow you to shape your sound ranging from minor adjustment to a complete change, warping or even building them from scratch. For those involved with composing, experimenting with many types of sounds is the key. Producing many types of sounds is known as sound design or programming a keyboard.
Oscillators, wave-forms, filters and envelope generators are some of the building blocks of sound design.
Sequencer is a device to record MIDI performance and play the recording back according to the sequence set in the user programme.
In the sampling process, the digital audio is recorded, manipulated or altered and played back. It is more real than any other form of sound synthesis as it involves real recorded sounds. You can add external audio clips in between your recorded files at desired locations.
Sampling has advanced quite a lot, since its introduction in 1980, due to reduction in digital memory costs. Today's keyboards in conjunction with advanced computer softwares can produce very rich and realistic sounds.
Input / output
The number and types of Input / Outputs requires a careful consideration before buying any keyboard. These can include jacks and connectors for DC Power, headphones, Audio In, Line Out, Sustain pedal, MIDI, Computer, Microphones, Display monitors, Amplifiers, mixers, speakers, storage devices etc.
If you are into live performance, audio output connections to amplifiers and mixers will most certainly be required. This is usually labelled as Line Out or Audio Out. If you make use of digital workstations, audio In / Out connections are a must.
You may want to save your song data from your keyboard to an external storage device or load external song data to your keyboard’s memory. Data regarding styles, effects, tones etc is also stored in the internal memory of the electronic keyboard.
The external storage options include flash drives, SD memory cards, floppy disks etc. To use SD memory cards, the instruments are required to have slots for them.