This API lets you use MIDI files converted to Tonejs-compatible JSON format to play music in desmos using the tone function. It allows you to play music beyond the limitations of the "hear graph" feature. This API currently supports the following features:

• Tempo Will play the song back at the BPM set in the MIDI file, allows for timing flexability.
• Multi-track Support Has the ability to play multiple notes at the same time, though sometimes sounds off
• Beats Only supports up to 0.125 (1/8) beats, anything shorter may be held out too long or not played at all.
• Help Provides data required to play automatically
• ToneJS Compatible Compatible with any existing ToneJS MIDI data you might already have!

This can be in a browser, Deno, Node.JS, Electron, or something completely different.
As long as it supports ES6, it'll work.

This will allow you to use the API. Modifying the API file may be required in some contexts (eg Node.JS) to allow importing.

A good open-source MIDI editor that I use a lot is Signal, but you can use any MIDI editor you'd like. Once you have downloaded or created a MIDI file, head over to this site to convert your MIDI file to be compatible with ToneJS.

Please note, that this is NOT endorsed by ToneJS, and this API does NOT use ToneJS or any similar libraries. This API is only compatible with the ToneJS-compatible JSON-ified MIDI format, not any other ToneJS format.

The API is one function, so you're in luck! You can simply run it like this:

var MidiJSONToDesmos = (function () {
    ...
})();

var data = MidiJSONToDesmos({
    ...
});

console.log(data.lines);
console.log(data.interval);
console.log(data.timer);
console.log(data.b);

Copy the text from the lines property of the output.
Paste this directly into Desmos' Graphing Calculator.

Select the variable "b". Copy data from data.b and paste it into the b<=__ (maximum value) value on the variable.
Set the minimum value to 0, and the step to 0.25 or 0.125. (We recommend 0.125!)

Press the + button, and select "ticker". Copy the text from data.timer and paste it into the Run input.
Copy the text from data.interval and paste it into the Every ___ ms input. This allows it to have the correct tempo.

Press the button on the ticker to start the music. Listen to it go!

"Boku Wa Dare" by themirrazz - For Desmos MIDI JSON
Jingle Bells, Short MIDI Cover [MIDI](jingle berrs.mid) [JSON](jinnnngle belllllllllllllllllls.json)
Bad Apple by IOSYS [SHORT] Coming Soon
Never Gonna Give You Up by Rick Astley [SHORT] Coming Soon
Vandalize - ONE OK ROCK - Chorus Only Coming Soon