Electronic musical instrument in the context of "MIDI"

An orchestra (/ˈɔːrkɪstrə/ ; OR-ki-strə) is a large instrumental ensemble typical of classical music, which combines instruments from different families. There are typically four main sections of instruments:

• The string section, including the violin, viola, cello, and double bass
• The woodwind section, including the flute, oboe, clarinet, bassoon, and occasionally saxophone
• The brass section, including the French horn (commonly known as the "horn"), trumpet, trombone, cornet, and tuba, and sometimes euphonium
• The percussion section, including the timpani, snare drum, bass drum, cymbals, triangle, tambourine, tam-tam and mallet percussion instruments

Other instruments such as the piano, harpsichord, pipe organ, and celesta may sometimes appear in a fifth keyboard section or may stand alone as soloist instruments, as may the concert harp and, for performances of some modern compositions, electronic instruments, and guitars.

Headphones are a pair of small loudspeaker drivers worn on or around the head over a user's ears. They are electroacoustic transducers, which convert an electrical signal to a corresponding sound. Headphones let a single user listen to an audio source privately, in contrast to a loudspeaker, which emits sound into the open air for anyone nearby to hear. Headphones are also known as earphones or, colloquially, cans. Circumaural (around the ear) and supra-aural (over the ear) headphones use a band over the top of the head to hold the drivers in place. Another type, known as earbuds or earpieces, consists of individual units that plug into the user's ear canal; within that category have been developed cordless air buds using wireless technology. A third type are bone conduction headphones, which typically wrap around the back of the head and rest in front of the ear canal, leaving the ear canal open. In the context of telecommunication, a headset is a combination of a headphone and microphone.

Headphones connect to a signal source such as an audio amplifier, radio, CD player, portable media player, mobile phone, video game console, or electronic musical instrument, either directly using a cord, or using wireless technology such as Bluetooth, DECT or FM radio. The first headphones were developed in the late 19th century for use by switchboard operators, to keep their hands free. Initially, the audio quality was mediocre and a step forward was the invention of high fidelity headphones.

In music, the organ is a keyboard instrument of one or more pipe divisions or other means (generally woodwind or electric) for producing tones. The organs have usually two or three, sometimes up to five or more, manuals for playing with the hands and a pedalboard for playing with the feet. With the use of registers, several groups of pipes can be connected to one manual.

The organ has been used in various musical settings, particularly in classical music. Music written specifically for the organ is common from the Renaissance to the present day. Pipe organs, the most traditional type, operate by forcing air through pipes of varying sizes and materials, each producing a different pitch and tone. These instruments are commonly found in churches and concert halls, where they have long been associated with liturgical music and grand ceremonial occasions.

Electronic music broadly is a group of music genres that employ electronic musical instruments, circuitry-based music technology and software, or general-purpose electronics (such as personal computers) in its creation. It includes both music made using electronic and electromechanical means (electroacoustic music). Pure electronic instruments depend entirely on circuitry-based sound generation, for instance using devices such as an electronic oscillator, theremin, or synthesizer: no acoustic waves need to be previously generated by mechanical means and then converted into electrical signals. On the other hand, electromechanical instruments have mechanical parts such as strings or hammers that generate the sound waves, together with electric elements including magnetic pickups, power amplifiers and loudspeakers that convert the acoustic waves into electrical signals, process them and convert them back into sound waves. Such electromechanical devices include the telharmonium, Hammond organ, electric piano and electric guitar.

The first electronic musical devices were developed at the end of the 19th century. During the 1920s and 1930s, some electronic instruments were introduced and the first compositions featuring them were written. By the 1940s, magnetic audio tape allowed musicians to tape sounds and then modify them by changing the tape speed or direction, leading to the development of electroacoustic tape music in the 1940s in Egypt and France. Musique concrète, created in Paris in 1948, was based on editing together recorded fragments of natural and industrial sounds. Music produced solely from electronic generators was first produced in Germany in 1953 by Karlheinz Stockhausen. Electronic music was also created in Japan and the United States beginning in the 1950s and algorithmic composition with computers was first demonstrated in the same decade.

In sound and music, an envelope describes how a sound changes over time. For example, a piano key, when struck and held, creates a near-immediate initial sound which gradually decreases in volume to zero. An envelope may relate to elements such as amplitude (volume), frequency (with the use of filters) or pitch.

Envelope generators, which allow users to control the different stages of a sound, are common features of synthesizers, samplers, and other electronic musical instruments. The most common envelope generator is controlled with four parameters: attack, decay, sustain and release (ADSR).

A disc jockey, more commonly abbreviated as DJ, is a person who plays recorded music for an audience. Types of DJs include radio DJs (who host programs on music radio stations), club DJs (who work at nightclubs or music festivals), mobile DJs (who are hired to work at public and private events such as weddings, parties, or festivals), and turntablists (who use record players, usually turntables, to manipulate sounds on phonograph records). Originally, the "disc" in "disc jockey" referred to shellac and later vinyl records, but nowadays DJ is used as an all-encompassing term to also describe persons who mix music from other recording media such as cassettes, CDs or digital audio files on a CDJ, controller, or even a laptop. DJs may adopt the title "DJ" in front of their real names, adopted pseudonyms, or stage names.

DJs commonly use audio equipment that can play at least two sources of recorded music simultaneously. This enables them to blend tracks together to create transitions between recordings and develop unique mixes of songs. This can involve aligning the beats of the music sources so their rhythms and tempos do not clash when played together and enable a smooth transition from one song to another. DJs often use specialized DJ mixers, small audio mixers with crossfader and cue functions to blend or transition from one song to another. Mixers are also used to pre-listen to sources of recorded music in headphones and adjust upcoming tracks to mix with currently playing music. DJ software can be used with a DJ controller device to mix audio files on a computer instead of a console mixer. DJs may also use a microphone to speak to the audience; effects units such as reverb to create sound effects and electronic musical instruments such as drum machines and synthesizers.

A synthesizer (also synthesiser or synth) is an electronic musical instrument that generates audio signals. Synthesizers typically create sounds by generating waveforms through methods including subtractive synthesis, additive synthesis, and frequency modulation synthesis. These sounds may be altered by components such as filters, which cut or boost frequencies; envelopes, which control articulation, or how notes begin and end; and low-frequency oscillators, which modulate parameters such as pitch, volume, or filter characteristics affecting timbre. Synthesizers are typically played with keyboards or controlled by sequencers, software or other instruments, and can be synchronized to other equipment via MIDI.

Synthesizer-like instruments emerged in the United States in the mid-20th century with instruments such as the RCA Mark II, which was controlled with punch cards and used hundreds of vacuum tubes. The Moog synthesizer, developed by Robert Moog and first sold in 1964, is credited for pioneering concepts such as voltage-controlled oscillators, envelopes, noise generators, filters, and sequencers. In 1970, the smaller, cheaper Minimoog standardized synthesizers as self-contained instruments with built-in keyboards, unlike the larger modular synthesizers before it.

Consumer electronics, also known as home electronics, are electronic devices intended for everyday household use. Consumer electronics include those used for entertainment, communications, and recreation. Historically, these products were referred to as "black goods" in American English due to many products being housed in black or dark casings. This term is used to distinguish them from "white goods", which are meant for housekeeping tasks, such as washing machines and refrigerators. In British English, they are often called "brown goods" by producers and sellers. Since the 2010s, this distinction has been absent in big box consumer electronics stores, whose inventories include entertainment, communication, and home office devices, as well as home appliances.

Radio broadcasting in the early 20th century brought the first major consumer product, the broadcast receiver. Later products included telephones, televisions, calculators, cameras, video game consoles, mobile phones, personal computers, and MP3 players. In the 2010s, consumer electronics stores often sold GPS, automotive electronics (vehicle audio), video game consoles, electronic musical instruments (e.g., synthesizer keyboards), karaoke machines, digital cameras, and video players (VCRs in the 1980s and 1990s, followed by DVD players and Blu-ray players). Stores also sold smart light fixtures, network devices, camcorders, and smartphones. Some of the modern products being sold include virtual reality goggles, smart home devices that connect to the Internet, streaming devices, and wearable technology.