Tom

A music machine. Dial in a melody in seconds, snap a whole song together like Lego, or tune in to endless radio.
Seeded, parameterized, royalty-free. In your browser (even offline) or on the command line.

Open Tom • Web app • Radio • CLI • Share links • How it works

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Tom is named after the tokay gecko, one of the few lizards that sings (it's named after its own call: "to-KAY!"). Tom writes music on demand: a hook for a video, a loop for a game, a jingle that lands exactly on your end card, or a full three-minute song. Everything is generated from a seed, so the same seed and settings always produce the same music: the same notes, rhythm and sounds, on every computer. And because Tom writes it all, what you make is yours to use: no samples, no licenses, no Content ID claims.

The web app

wemiller.com/tools/tom runs entirely in your browser. Nothing is uploaded, and after your first visit it works offline: on iPhone or iPad, tap Share → Add to Home Screen and Tom opens like an app, with or without a connection.

Melody Machine

Press 🎲 New melody and you get one. Then dial it in:

Dial	What it does
Style	Synthwave, Bright Pop, Chiptune, Lo-fi, Marimba, Jazz, Orchestral, Hip-Hop, Rock, Reggae, EDM, Country, Funk
Key · Mode · Tempo	Any key; major, minor, dorian, mixolydian, pentatonic
Bars	4, 8 or 16
Busy-ness	Sparse and singable ↔ quick and chatty
Swing & syncopation	On the beat ↔ pushing against it
Shape	Arch, rise, fall, wave or flat: the overall contour of the line
Phrase form	AABA, ABAB, AAAB, ABAC, ABCD: which bars repeat the hook
Register	Low, mid or high
Chords	About 35 progressions, from I–V–vi–IV to ii7–V7–Imaj7 and i–VII–VI–V7, or type your own (see below)
Sound	What plays the melody: the style's own voice, or any of about 35 others (kalimba, sax, harp, steel pan, harmonica…)
Backing · Drums	Chords and bass on/off, drum density

Type your own chords in the box under Chords, as scale degrees (1-5-6-4) or Roman numerals (vi-IV-I-V), each with an optional color:

You type	You get (in C)
Imaj7 ii7 V7 vi9 I6	sevenths, ninths and sixths: Cmaj7, Dm7, G7, Am9, C6. V7 is always a dominant, in minor keys too.
IVadd9 Vsus4 Isus2	added ninths and suspensions
IVm IM viidim	a different quality: the minor iv borrowed from C minor, a major I, a diminished vii
bVII bVI bIII bII	major chords borrowed from the parallel key: Bb, Ab, Eb, Db
V/V V7/ii IV/IV	a chord built on another degree: D (V of V), A7 (V7 of ii)
I:2,V:2,vi:4	how many beats each chord lasts (default 4)

Turning a dial keeps the seed, so you're shaping this melody rather than getting a new one. The piano roll shows every note, and Add to composer → drops it into a song.

Next to Play, the scrub bar under the clock jumps anywhere in what's playing (drag it while stopped to choose where Play starts), and the volume slider and mute button apply to every mode.

Composer

Songs are built from blocks, like Lego bricks: Intro, Verse, Build, Chorus, Break, Outro and an Ending hit. Click or drag bricks onto the timeline and reorder them. Select a brick to shape it: length, chords (a preset, or type your own as above), layers (chords, arp, bass, melody, counter-melody, bells, octave doubling, riser, crash), drum level, filter sweep, and the same melody dials.

🔁 Loop any blocks to practise or jam over them: tap 🔁 on the bricks you want and they play in order, round and round (mark blocks 2 and 3 and you hear 2, 3, 2, 3…), until you take a block out of the loop or switch Loop off.

Sounds: under the song's key and tempo, pick what plays the melody, the counter-line and the bells. Each menu starts with the style's own voice and the sounds that suit the style, then every other sound Tom has.

✨ Auto does the heavy lifting whenever you want:

• Build a whole song: a full (~3 min), short (~1 min) or loop arrangement, with choruses that share one hook.
• Finish my song: keeps what you've made and adds the rest of the arrangement, ending with a proper outro and final hit.
• Surprise me: re-rolls just the selected block.
• Re-roll everything unlocked: 🔒 Lock any block you love, and Auto will never touch it.

Export gives you WAV audio, a MIDI file (one track per layer, General MIDI drums) for Logic, GarageBand or Ableton, or the song as JSON. Your work autosaves in the browser.

Radio

Pick a station, one per style plus Mix, which rotates through every style, and Tom writes an endless run of brand-new songs in it: a fresh tag, key and tempo for each, mostly full-length, and each with its own song form, section lengths and textures. Tom stays two songs ahead of the one playing, so the gaps between songs are just the ring-out of each ending.

• It keeps playing in the background. Radio plays through a media element rather than Web Audio, so on iPhone it carries on with the screen locked, with Safari in the background, and with the ringer switch on silent. The lock screen and Control Center show the song and station, with play, pause, next and scrubbing. If a song isn't written yet when the last one ends, Radio holds the line with silence (iOS stops a page that goes quiet) and starts the song as soon as it's ready.
• Every song is a real song. Open in the composer takes the one you're hearing into the composer to keep editing, and Copy link gives its #song: link, the same song for anyone.
• Pick what the Mix plays: toggle styles on and off under the stations.
• Previous and next on the lock screen, in Control Center and in CarPlay, not ±10 s skips. Previous goes back a song (or restarts one you're a few seconds into).
• Songs you've heard: everything Radio plays is listed, with ☆ Saved for keepers. Play any song again, open it in the composer or copy its link. Your station, Mix styles and history are remembered on your device.
• Siri, Shortcuts and CarPlay: wemiller.com/tools/tom/app/#radio:jazz&play opens the Jazz station and starts it. Put that in a Shortcut's Open URLs action and "Hey Siri, Jazz Radio" opens it. iOS needs one tap before a web page can play sound, so the whole screen becomes a start button; after that it's in Now Playing, CarPlay included. (A web page can't be a CarPlay app of its own; that needs a native app.)
• wemiller.com/tools/tom/app/#radio:jazz opens the Jazz station; #radio:mix&styles=jazz,funk a Mix of just those.

Share links: a hashtag is a song

The seed lives in the URL, so the link is the song:

wemiller.com/tools/tom/app/#sunset-drive                        a melody; the tag alone picks style, key, tempo and shape
wemiller.com/tools/tom/app/#sunset-drive&style=chip&busy=0.8    the same tag with a couple of dials turned
wemiller.com/tools/tom/app/#first-dance&style=jazz&key=Bb&bpm=132   any tag, in any style
wemiller.com/tools/tom/app/#song:road-trip&length=short         a whole auto-built song from a tag
wemiller.com/tools/tom/app/#song:road-trip&gen=3                the same tag through the newest arranger (varied forms, richer chords, its own sounds)
wemiller.com/tools/tom/app/#song=eyJ2ZXJzaW9uIjox…               an edited song, carried in full

Type any word after the # and Tom plays that song, the same one for everyone, every time. The address bar updates as you work, so copying it always copies exactly what you hear. Links list only the dials that differ from the tag's own recipe, so they stay short. A link, once shared, keeps its song: bare tags choose among the original five styles forever, so adding styles never changes an existing link (the tests pin every note of a set of golden links). New styles are one &style= away. The die rolls memorable tags like #mellow-gecko-42.

The CLI reads the same links and prints one for every render, so a song moves between the browser and the terminal without changing a note.

The CLI

Zero dependencies; Node 18 or newer. ffmpeg is optional and adds .m4a/.mp3 output plus loudness normalization (−14 LUFS by default).

git clone https://github.com/blaineam/Tom.git && cd Tom
node tom.mjs help                 # or: ln -s "$PWD/bin/tom" /usr/local/bin/tom

tom melody --seed '#sunset-drive' --out hook.wav --midi       # the same melody as the link above
tom melody --style chip --density 0.8 --contour rise --form AAAB --bars 16
tom song --seed road-trip --length short --out road-trip.m4a --blueprint
tom jingle --style synthwave --length 9.1 --hit 6.75 --out bed.wav
tom render 'https://wemiller.com/tools/tom/app/#sunset-drive&busy=0.8'  # any share link
tom render my-song.json                                       # a song saved from the composer
tom radio --station funk --count 5 --format m4a                # the next five songs of a radio station
tom compose                                                   # run the web app locally
tom styles | tom doctor

Command	Makes
tom melody	A melody over a backing loop. Every Melody Machine dial is a flag: --bars --density --syncopation --contour --form --octave --progression --no-chords --no-bass --drums.
tom song	A whole auto-arranged song. --length full|short|loop
tom jingle	A short bed whose final hit lands exactly at --hit seconds and rings out to --length. Tempo is solved so the hit falls on a bar line, which makes it ideal for video end cards.
tom render	A composer song (.json), a share link, or a bare #hashtag.
tom radio	The next few songs of a station, one file each, into a folder. --station <style|mix> --count 3 --seed <s> --out <dir> --format wav|m4a|mp3. The same --seed gives the same songs.
tom compose	Serves the web app at http://127.0.0.1:5178.

Common flags: --style, --seed (any word or #hashtag), --key (e.g. A, F#, Eb), --mode, --bpm, --out, --midi [file], --blueprint [file], --loudness <LUFS>.

With Monkr

Monkr animates device mockups into video. When tom is installed, monkr animate --music <style> scores the clip with a Tom jingle whose final hit lands where you ask.

Styles

Style	Sound
Synthwave	Saw arpeggios, gated reverb snare, a pad that pumps with the kick
Bright Pop	Plucked arps, claps, sidechained supersaw
Chiptune	Square-wave lead, triangle bass, noise drums
Lo-fi	Swung FM electric piano, soft drums, vinyl crackle
Marimba	Warm marimba melody, shaker, soft pad
Jazz	Walking upright bass that steps chromatically into each chord, swung ride and brushes, rootless piano comping, vibraphone melody over ii–V–I changes
Orchestral	Swelling divided strings, french-horn melody, pizzicato, low strings, timpani tuned to the key (and timpani rolls into each chorus), concert-hall reverb
Hip-Hop	Boom-bap drums with swung hats and ghost notes, snare layered with a clap, an 808 that slides into pitch and lands with every kick, dusty electric-piano chords, a breathy flute hook
Rock	Distorted power chords (palm-muted chugs in verses, open ringing chords in choruses), driving picked bass, a roomy kit with a tom fill every fourth bar, an overdriven lead guitar on the melody
Reggae	One-drop drums (nothing on the one; kick and rimshot together on three), guitar skank on 2 and 4, organ bubble on the off-beats, a deep dub bass that leaves space, a melodica lead through dub echo
EDM	Four-on-the-floor kick, claps and off-beat open hats, hard-pumping sidechained supersaw chords, an off-beat house bassline, 16th-note saw-pluck arps, a supersaw lead, and builds that roll and rise into the drop
Country	Boom-chick: bass alternating root and fifth on 1 and 3 (walking up into each chord change) with an acoustic strum on 2 and 4, a brushed two-step, banjo forward rolls, a pedal-steel melody that swells and slides into its notes, and a fiddle
Funk	A syncopated 16th-note groove with snare ghost notes and an open hat on the "and" of 4, slap bass that pops the octave and leans on the flat seven, chicken-scratch guitar on 9th chords, keys in the verses, horn-section stabs in the choruses, and a brass lead

How it works

• Blueprints. A song is a JSON list of blocks. Each block says which layers play and how its melody is shaped; each style says how those layers sound. The web app, the CLI and share links all produce the same blueprint for the same input.
• Melodies with memory. A motif (a bar of rhythm plus a melodic shape) is invented for each letter of the phrase form, then replayed. That repetition is what makes a tune hummable instead of a random walk. The contour steers the line, strong beats land on chord tones, every leap is answered by a step back, there are no tritone leaps, and the phrase resolves to the tonic.
• Synthesis from scratch. Band-limited oscillators, Karplus–Strong plucks, FM electric piano and chimes, biquad filters, a Freeverb reverb, echo, kick-driven sidechain and a soft-clipping master bus, all in plain JavaScript on Float32Arrays. The same code runs in Node and in a Web Worker in the browser.
• Deterministic. Every random choice comes from a seeded generator, and each layer draws from its own forked stream, so changing one part never reshuffles another. The notes are identical everywhere. On one machine the audio is byte-identical too; across different CPUs, sin/exp can round differently in the last bit, far below anything audible.

lib/
  rng.mjs         seeded randomness (mulberry32, forkable streams)
  dsp.mjs         oscillators, envelopes, filters, reverb, mix bus
  instruments.mjs drums, plucks, pads, leads, bass
  theory.mjs      scales, chords, progressions, the melody generator
  styles.mjs      the styles (synthwave, pop, chip, lofi, marimba, jazz, orchestral, hiphop, rock, reggae, edm, country, funk)
  sounds.mjs      the melodic sound pool, and which sounds suit each style
  blueprint.mjs   blocks, Auto song / finish / surprise, jingles, melodies
  arrange.mjs     blueprint → audio + note events
  share.mjs       hashtag seeds and share links
  radio.mjs       stations: track n of a station, as a song with its own link
  wav.mjs midi.mjs  file writers
web/              the web app (no build step); sw.js caches it for offline use
tom.mjs           the CLI

Run the tests with npm test.

License

MIT © 2026 Blaine Miller. Music you make with Tom is yours.