The output is a standard MIDI file: note numbers, positions and lengths. There is no audio in it. Opening it in a DAW plays it through whatever instrument that track is pointed at, which is the whole point — the same phrase can be a piano, a synth lead or a string section depending on what you assign.
AI MIDI Generator for Short Phrases
Generate a MIDI phrase from a key, tempo and part. Pick melody, chords, bass or arpeggio, set the bars, and download a file you can drop into any DAW.
Set a key, a tempo and which part you want, then generate. What comes back is a short MIDI phrase you can download and open in any editor — notes and timing, not audio.
01
What You Get, and What You Do Not
That also means it does not sound like anything on its own. If you were expecting a finished loop you can drop into a video, a MIDI file is the wrong format and the music generator on this site is the right one.
Phrases are four, eight or sixteen bars in 4/4. That is deliberate: these are building blocks meant to be looped, transposed and edited, not arrangements. Asking a language model for a full song structure produces something that holds together much less well than a short phrase does.
02
Choosing the Part
Melody gives mostly one note at a time, the kind of line you would sing or play as a lead. Chords stack simultaneous notes, which is what you want as a harmonic bed under something else. Bass stays in the low register and tends toward longer notes on strong beats. Arpeggio breaks a chord into steady subdivisions, which is the busiest of the four and the most useful as movement under a sparse melody.
The practical way to use this is one part at a time rather than asking for everything at once. Generate chords first, listen to where they go, then generate a melody in the same key and tempo and see whether it sits on top. Two separate requests give you two tracks you can align and edit independently; one request for both gives you a single track you have to split by hand.
If you need a specific voicing or a particular shape, say so in the extra direction field — something like starting on the fifth, or leaving space on beat three, changes the result more reliably than switching genre does.
03
What to Expect from the Result
A language model generating notes is good at staying in key and producing plausible rhythm, and weaker at long-range structure. Inside four or eight bars that is usually fine. At sixteen bars you will more often get something that drifts rather than developing, which is the main reason to start short.
Expect to edit. The most common fixes are nudging one or two notes that sit awkwardly, and trimming the last note so the phrase loops cleanly. Both are seconds of work in a piano roll and neither means the generation failed.
Results vary between attempts even with identical settings, which is useful rather than a flaw: generating three times and keeping the best is faster than trying to describe exactly what you want in words.
04
How the Notes Are Handled
Notes are requested in beats rather than seconds, because asking a model to multiply by the tempo itself is a reliable way to get the timing wrong. The conversion to seconds happens afterwards, when the MIDI file is written.
Model output is then checked rather than trusted. Pitches outside the MIDI range are clamped instead of discarded, notes that start past the final bar are dropped, and notes that run past the end are trimmed to it. A broken duration falls back to one beat rather than losing a note the model clearly meant to place, and notes too short to be audible are removed because they only clutter the piano roll.
The tempo you set is written into the file header, so bar lines line up when you import it. Nothing about the notes depends on that value — changing the project tempo afterwards stretches the phrase as you would expect.
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What People Use Generated MIDI For
Breaking a blank page is the most common reason. A generated phrase in the key you are working in gives you something to react to, and reacting is usually easier than starting. Most people keep a fragment and rewrite the rest.
Producers use it for parts outside their instrument. A guitarist who does not think in keyboard voicings can generate a chord bed; someone who writes chords easily but struggles with bass can generate a line and then simplify it.
People learning theory use it as a worked example: generate a progression in a key, look at which degrees it uses, and compare that against what you expected. Because the output is notes rather than audio, you can see the answer rather than having to transcribe it.
If you have audio rather than a prompt, the audio-to-MIDI tool on this site transcribes an existing recording instead, which is the better route when you already know how the part should go.
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AI MIDI Generator Questions
Does the file contain audio?
No. A MIDI file holds notes and timing only. It plays through whichever instrument your DAW assigns to the track, which is why the same phrase can be a piano or a synth.
Why do I need to sign in?
Each generation spends a model request on our side. Requiring an account keeps that from being used anonymously at scale.
Why does the same setting give a different result each time?
Generation is not deterministic. That is useful here: running it three times and keeping the best is usually faster than trying to describe precisely what you want.
Can it generate a full song?
No, and that is on purpose. Four to sixteen bars is where this holds together. Longer requests drift rather than develop, so generate parts and arrange them yourself.
Can I get drums?
Not yet. Percussion in MIDI depends on a drum map rather than pitches, which needs different handling from the melodic parts.
What does the extra direction field do?
It is appended to the request. Concrete musical instructions work best — a starting interval, a rhythm to avoid, a register. Vague adjectives change the result less than the genre and mood selectors already do.
Which tempo should I set?
The one your project is at. The value is written into the file header so bar lines align on import; the notes themselves are positioned in beats, so a later tempo change stretches the phrase correctly.