Rithmatic: FM Synth & Patches

Rithmatic is an FM synthesizer and DX7 patch library with 36,118 classic voices built in. Browse them by family and by character, learn how FM synthesis works by watching it shape each one, build and blend your own in a six-operator patch editor, and play them from the on-screen keys or a MIDI keyboard. No account, no ads, nothing locked.

A LIBRARY THAT SHIPS FULL
• 36,118 unique DX7 voices come with the app. No download, no account, no network: they are there the first time you open it.
• Start with Essentials: the famous sounds and the songs they're on.
• Browse by family (keys, bass, brass and winds, strings, organs, bells and more) or by character: percussive, plucked, metallic, bright, sustained, swell, evolving, mellow. Or search by name.
• Near duplicates are folded away, so each sound shows once.
• Patch of the day: one classic voice each day, at the top of the patch picker.
• Every voice is credited to the archive it came from, and to its designer where a bank names one.

PLAY IT
• A DX7-compatible synthesis engine runs inside the app, so every patch plays with nothing plugged in.
• Play from the on-screen keys or any MIDI keyboard you connect.
• Pitch bend, mod wheel, breath, sustain and aftertouch, with aftertouch set to vibrato, tremolo or swell.
• Velocity from a MIDI keyboard, or turn it off and choose how hard every note plays.
• An arpeggiator (up, down, up and down, random or as played, over up to three octaves) and a latch that holds each key.
• Record what you play and share it as a WAV.
• Five tunings: equal, just, and Wendy Carlos's Alpha, Beta and Gamma scales.
• Light or dark, as your device is set or as you choose. Drag the keys taller or shorter.
• Keys, shortcuts and every synth term, explained in Settings under Help & support.

SEE THE SOUND
The waveform follows what you play: each operator's envelope, how hard you hit, the pitch, the LFO's wobble, and a chord as one layer per note. Resize it, open it full screen, or switch to the Scope look, an oscilloscope of the output itself.

PATCH BUILDER AND EDITOR: LEARN HOW FM WORKS
FM is famous for being hard to program. The Patch Builder shows you why a sound sounds the way it does, so you learn FM by playing with it, not by reading charts.
• All six operators on a graph, each cable carrying its wave: see a modulator reshape its carrier as you drag.
• Draw a cable and the builder snaps to the nearest of the 32 algorithms, so you learn routing by doing it.
• Plain words beside the jargon. Edit each operator's ratio, level, envelope and tuning, the LFO and pitch envelope, or use FEEL: thickness, touch and brightness.

BLEND
Pick two patches and Rithmatic blends them into eight new ones. Play each, and keep the ones you like.

YOUR BANK, SYSEX AND FILES
• Gather patches from anywhere into your bank, then drag pads to swap or reorder them.
• Export the bank as standard DX7 .syx SysEx files. Open .syx banks, or a .zip of them, from your files, email or the share sheet.
• Share a sound as a short clip of it playing, with a card and a code that brings the patch into anyone's Rithmatic.

WITH A SYNTH, IF YOU HAVE ONE
Hardware is optional. Choose your synth in Settings:
• Korg Volca FM2 (firmware 1.10 or later, over MIDI): read its current patch, write to any of its 64 memory slots, back up and restore all 16 sequencer patterns, and capture the whole instrument to a snapshot. A full two-way editor and librarian.
• DX7 family: send patches and 32-voice banks to a DX7 (mkI/II), TX7, TX802 or the original Volca FM over standard Yamaha voice dumps.

FREE AND PRIVATE
Every feature is free. An optional tip in Settings unlocks nothing. Rithmatic works offline, keeps your files on your device, and collects no personal data: no account, no analytics, no ads.

KORG and volca are trademarks of Korg Inc. DX7 and TX are trademarks of Yamaha Corporation. Rithmatic is an independent app and is not affiliated with or endorsed by either.

Recent changes:
Dark mode, five tunings, resizable keys and Help.

- Dark mode: follows your device, or pick it in Settings
- Tuning: equal, just, or Wendy Carlos's Alpha, Beta, Gamma
- Drag the top of the keys to resize them
- Keys, shortcuts and synth terms in Settings > Help
- Clearer contrast; Blend plays without hardware

Still new from 1.1: Essentials, the famous DX7 sounds; Patch Builder envelopes and LFO; Blend; an arpeggiator; mono and glide; a truer DX7; every MIDI keyboard plays