Music sequencer

 ( Electronic Musical Instruments ) 

A music sequencer (or audio sequencer

Many modern sequencers can be used to control virtual instruments implemented as software Audio plug-in. This allows musicians to replace expensive and cumbersome standalone synthesizers with their software equivalents.

Today the term sequencer is often used to describe software. However, hardware sequencers still exist. Workstation keyboards have their own proprietary built-in MIDI sequencers. and some older synthesizers have their own step sequencer built in. The market demand for standalone hardware MIDI sequencers has diminished greatly due to the greater feature set of their software counterparts.

• MIDI data for MIDI sequencers

 
Joseph Rothstein (1995). 9780895793096, A-R Editions, Inc.. ISBN 9780895793096
     

• CV/Gate data for

 
 (2025). 9780674042162, Harvard University Press. ISBN 9780674042162
     

• Automation data for mix automation in DAWs, and software effect or instrument Audio plugin for DAWs with sequencing features
• Audio signal data in

Also, a music sequencer can be categorized by its construction and supported modes.

On step sequencers, musical notes are rounded into steps of equal time intervals, and users can enter each musical note without exact timing; Instead, the timing and duration of each step can be designated in several different ways:

• On the : select a trigger timing from a row of step-buttons.
• On the bass machines: select a step note (or rest) from a chromatic keypad, then select a step duration (or tie) from a group of length-buttons, sequentially.
• On the several home keyboards: in addition to the real-time sequencer, a pair of step trigger buttons is provided; using it, notes on the pre-recorded sequence can be triggered in arbitrary timings for the timing dedicated recordings or performances. (See ).

In general, step mode, along with roughly quantized semi-realtime mode, is often supported on the drum machines, bass machines and several groovebox.

The origin of automatic musical instruments seems remarkably old. As early as the 9th century, the Persian people (Iranian) Banū Mūsā brothers invented a organ using exchangeable cylinders with pins,

and also an automation flute-playing machine using steam power,

In 1206, Al-Jazari, an Arab engineer, invented programmable musical automata, a "robot Musical ensemble" which performed "more than fifty facial and body actions during each musical selection." It was notably the first programmable drum machine. Among the four automaton musicians were two drummers. It was a drum machine where (cams) bump into little that operated the percussion. The drummers could be made to play different rhythms and different drum patterns if the pegs were moved around.Noel Sharkey, A 13th Century Programmable Robot (Archive), University of Sheffield.

In the 14th century, rotating cylinders with pins were used to play a carillon (steam organ) in Flanders, and at least in the 15th century, were seen in the Netherlands.

In the late-18th or early-19th century, with technological advances of the Industrial Revolution various automatic musical instruments were invented. Some examples: , and consisting of a barrel or cylinder with pins or a flat metal disc with punched holes; or , and using book music / () with punched holes, etc. These instruments were disseminated widely as popular entertainment devices prior to the inventions of , , and which eventually eclipsed all such home music production devices. Of them all, punched-paper-tape media had been used until the mid-20th century. The earliest programmable music synthesizers including the RCA Mark II Sound Synthesizer in 1957, and the Siemens Synthesizer in 1959, were also controlled via similar to . —( PDF version is available)

Additional inventions grew out of sound film audio technology. The drawn sound technique which appeared in the late 1920s, is notable as a precursor of today's intuitive graphical user interfaces. In this technique, notes and various sound parameters are triggered by hand-drawn black ink waveforms directly upon the film substrate, hence they resemble piano rolls (or the 'strip charts' of the modern sequencers/DAWs). Drawn soundtrack was often used in early experimental electronic music, including the Variophone developed by Yevgeny Sholpo in 1930, and the Oramics designed by Daphne Oram in 1957, and so forth.

In 1965, [[Max Mathews]] and L. Rosler developed Graphic 1, an interactive [[graphical sound]] system  (that implies sequencer) on which one could draw figures using a light-pen that would be converted into sound, simplifying the process of composing computer-generated music.
Thom Holmes (2025). 9780415957816, Taylor & Francis. ISBN 9780415957816 It used PDP-5 minicomputer for data input, and IBM 7094 mainframe computer for rendering sound.