A recurring idea: store instructions, then perform them
Sequencer history is a history of different ways to describe a performance. A paper roll, a row of control voltages and a digital note list are different media, but each can specify events that an instrument carries out in time. This overview follows those ideas rather than naming a single inventor or a definitive first sequencer.
Player-piano rolls: music encoded in a physical object
Player pianos provide a useful early example. Perforations in a paper roll tell the mechanism which notes to play; longer holes can encode longer notes. The Science Museum Group collection includes Aeolian pianola rolls made between 1921 and 1930. This is stored performance information, rather than a recording of the resulting sound.
Analog step sequencing: repeated values and triggers
Analog step sequencers make the repeating list visible as knobs and switches. A clock advances the active step, while control-voltage and gate outputs can control an external synthesizer. A short sequence becomes a musical part through repetition and hands-on changes.
The Doepfer A-155 is a documented example of this design: it provides eight-step analog rows and trigger/gate rows. It illustrates the operating principle, rather than establishing when analog sequencing was first invented.
Programmable drum machines make rhythm a grid
Drum machines bring sound generation and pattern programming into one instrument. The TR-808, introduced by Roland in 1980, is a widely recognized example. Its step-based workflow lets a musician place individual drum hits and repeat a pattern without performing every hit live.
That visible relationship between a position and a sound still appears in many software drum grids. A contemporary browser grid is a new interface to a familiar idea: divide time, choose the events and listen to the result.
Source: Roland: The TR-808 Story
MIDI lets instruments exchange musical messages
MIDI extended sequencing beyond one device’s internal sound generator. Note and control messages can travel between compatible instruments. A well-known public demonstration linked a Sequential Prophet-600 and Roland Jupiter-6 at the 1983 NAMM show.
The MIDI Association’s historical account also describes the longer process of development and adoption. One demonstration was a milestone in a continuing effort, not an overnight replacement for every earlier system. MIDI messages describe musical actions; they are not the audio waveform.
Software brings several editing scales together
Computer music software can combine a piano roll for individual notes, patterns or clips for repeated phrases and a timeline for longer arrangements. The same project can be edited at these different scales. Software also makes copying, undoing and saving versions convenient.
A DAW may add audio recording, mixing, effects and external control. The presence of a sequencer inside a DAW does not make every smaller sequencer a complete recording studio. The useful comparison is the task you need it to perform.
The browser becomes another place to make a sequence
Web Audio gives web applications audio processing and synthesis building blocks. A browser tool can turn a note grid into sound without installing a conventional music application. Audio timing, device resources and browser lifecycle still need careful handling.
Float Sequencer uses that approach for quick local sketches: synthesized tracks, eight patterns and a short arrangement, with JSON backups and WAV export. It currently has no MIDI connection or recording feature. Learning the relationship between steps, patterns and arrangements transfers well even when you later choose a different instrument.
Source: MDN: Web Audio API