A MIDI guitar sends data, not sound
Acoustic and electric guitars send audio down a cable. A MIDI guitar sends instructions: "string 4, note D3, velocity 92, released 340 ms later". The sound you hear comes from whatever receives those instructions.
That is why the same guitar can play a piano, a string section or a synth pad. The instrument is a controller; the tone is chosen downstream.
Two ways to capture what the strings are doing
The traditional route is a hexaphonic pickup: six individual pickups, one per string, feeding a converter that measures pitch per string. Separate sensing is what lets it follow six simultaneous notes.
The newer route is position sensing. Instruments such as Jamstik and Aeroband watch where the strings are pressed and struck rather than analysing raw audio, which cuts tracking lag and removes the need for a converter box.
Tracking delay is the real limitation
Any pitch-to-MIDI system must hear enough of a note to identify it. Low notes need more cycles, so they take longer โ which is why fast bass lines on the low E are the hardest thing to track.
Good technique helps more than any setting: play staccato, avoid bending while the converter is measuring, and keep the low strings clean. A pickup that "mishears" is usually reacting to messy input.
What the browser does with those messages
Web MIDI gives a page access to the connected inputs. Each incoming message carries a note number, a velocity and a channel, and the page maps that number onto its own instrument โ a modelled guitar, a piano or a synth.
Because the mapping is just numbers, the browser can also show you where the note sits on the fretboard. Play a MIDI note and it can highlight the lowest comfortable string and fret, which turns a controller into a fingering trainer.
Do you need a MIDI pickup to start?
No. If you want to see what MIDI guitar feels like, a browser instrument driven by a keyboard controller covers the same ground: the same note numbers, velocity and sustain messages arrive either way.
Buy a hexaphonic pickup or a dedicated MIDI guitar when you specifically need six-string tracking for performance. For learning the workflow, the browser path costs nothing.
Frequently Asked Questions
- What is a MIDI guitar?
- A MIDI guitar is a guitar that outputs note data rather than audio. It converts pitch, velocity and timing from each string into MIDI messages, which a synth, sampler or browser turns into sound.
- Does a MIDI guitar sound like a guitar?
- It only sounds like a guitar if you point it at guitar sounds. The guitar itself produces no tone of its own โ the receiving device decides, so it can sound like a piano, strings or a synth.
- Can I use a normal guitar as a MIDI controller?
- Not without hardware. A standard guitar needs a hexaphonic pickup and converter, or a pitch-to-MIDI pedal, to produce MIDI. Only purpose-built instruments such as Jamstik sense the fingerboard directly.