Electronic keyboard in the context of "Headphone jack"

A musical keyboard is the set of adjacent depressible levers or keys on a musical instrument. Keyboards typically contain keys for playing the twelve notes of the Western musical scale, with a combination of larger, longer keys and smaller, shorter keys that repeats at the interval of an octave. Pressing a key on the keyboard makes the instrument produce sounds—either by mechanically striking a string or tine (acoustic and electric piano, clavichord), plucking a string (harpsichord), causing air to flow through a pipe organ, striking a bell (carillon), or activating an electronic circuit (synthesizer, digital piano, electronic keyboard). Since the most commonly encountered keyboard instrument is the piano, the keyboard layout is often referred to as the piano keyboard or simply piano keys.

A keyboard instrument is a musical instrument played using a keyboard, a row of levers that are pressed by the fingers. The most common of these are the piano, organ, and various electronic keyboards, including synthesizers and digital pianos. Other keyboard instruments include celestas, which are struck idiophones operated by a keyboard, and carillons, which are usually housed in bell towers or belfries of churches or municipal buildings.

Today, the term keyboard often refers to keyboard-style synthesizers and arrangers as well as work-stations. These keyboards typically work by translating the physical act of pressing keys into electrical signals that produce sound. Under the fingers of a sensitive performer, the keyboard may also be used to control dynamics, phrasing, shading, articulation, and other elements of expression—depending on the design and inherent capabilities of the instrument. Modern keyboards, especially digital ones, can simulate a wide range of sounds beyond traditional piano tones, thanks to advanced sound synthesis techniques and digital sampling technology.

An electric organ, also known as electronic organ, is an electronic keyboard instrument which was derived from the harmonium, pipe organ and theatre organ. Originally designed to imitate their sound, or orchestral sounds, it has since developed into several types of instruments:

• Hammond-style organs used in many styles of popular music including Pop, Rock, Country, Blues, Gospel and Jazz;

• digital church organs, which imitate pipe organs and are used primarily in churches;
• other types including combo organs, home organs, and software organs.

A digital piano is a class of electronic keyboard or synthesizer (rompler) designed to serve primarily as an alternative to the traditional acoustic piano, both in how it feels to play and in the sound it produces. Digital pianos use either synthesized emulation or recorded samples of an acoustic piano, which are played through one or more internal loudspeakers. They also incorporate weighted keys, which recreate the feel of an acoustic piano. Some digital pianos are designed to also look like an upright or grand piano. Others may be very simple, without a stand.

While digital pianos may sometimes fall short of acoustic ones in feel and sound, their advantages include being smaller, weighing much less, and costing less than an acoustic piano. In addition, they do not need to be tuned, and their tuning can be modified to match the tuning of another instrument (e.g. a pipe organ). Like other electronic musical instruments, they can be connected to an amplifier or a PA system to produce a sound loud enough for a large venue or, at the other extreme, may be heard through headphones only. Some digital pianos can emulate other sounds besides the piano, the most common ones being pipe organ, electric piano, Hammond organ, and harpsichord. Digital pianos are often used in music schools and music studios as a replacement for traditional instruments.

Musical Instrument Digital Interface (/ˈmɪdi/; MIDI) is an American-Japanese technical standard that describes a communication protocol, digital interface, and electrical connectors that connect a wide variety of electronic musical instruments, computers, and related audio devices for playing, editing, and recording music. A single MIDI cable can carry up to sixteen channels of MIDI data, each of which can be routed to a separate device. Each interaction with a key, button, knob or slider is converted into a MIDI event, which specifies musical instructions, such as a note's pitch, timing and velocity. One common MIDI application is to play a MIDI keyboard or other controller and use it to trigger a digital sound module (which contains synthesized musical sounds) to generate sounds, which the audience hears produced by a keyboard amplifier. MIDI data can be transferred via MIDI or USB cable, or recorded to a sequencer or digital audio workstation to be edited or played back.

MIDI also defines a file format that stores and exchanges the data. Advantages of MIDI include small file size, ease of modification and manipulation and a wide choice of electronic instruments and synthesizer or digitally sampled sounds. A MIDI recording of a performance on a keyboard could sound like a piano or other keyboard instrument; however, since MIDI records the messages and information about their notes and not the specific sounds, this recording could be changed to many other sounds, ranging from synthesized or sampled guitar or flute to full orchestra.