Comparison

Beat Kitchen Harmonic Synth vs Rithmatic

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Beat Kitchen Harmonic Synth

Shape the overtone series directly to create unique sounds. This additive synthesizer allows real-time manipulation of harmonics, LFOs, and envelopes. Explore sound design and synthesis on your device.

Highlights
  • Additive synthesis engine
  • Overtone series shaping
  • Live waveform and spectrum response
  • Modulation matrix with LFOs and envelopes
  • AUv3 support
  • On-device processing
Features
Read full description

BKS Harmonic is an additive synthesizer that builds sound from individual overtones, then gives you tools to shape, scan and filter them by harmony. Load it as an Audio Unit v3 inside AUM, GarageBand, Cubasis, Loopy Pro or any AUv3 host, or run it standalone. A TUNER THAT KNOWS ABOUT STRETCH Tune mode turns the scope into a tuner: it names the note it hears and shows how far sharp or flat it is in cents, with a ring that closes as you land on the pitch. It tunes against the stretch curve rather than equal temperament, so it follows a real instrument. Stretch shapes the overtones inside a note; Key Stretch makes the keyboard follow it, so octaves widen the way a piano's do. FOURTEEN TUNING SYSTEMS, AND A TEMPERAMENT EDITOR Equal and Just, five historical temperaments, and six from outside the European tradition including Maqam Rast, Turkish Rast, Slendro, Pelog and the Harmonic Series. The Temperament slider is a morph, not a switch: fully left is Just, fully right is whichever you chose. Twelve bars show any system as cents away from equal; drag one to make the tuning yours, then copy it out as plain text. Tunings save with the preset. FIVE HUNDRED SCALES Searchable by alternate name: malkauns, nikriz, bhupali and freygish find the right set. THE PARTIALS ARE THE INSTRUMENT The partials display shows every overtone in your sound, and four tools work on it directly. FOLD sweeps upper partials below the fundamental, redistributing energy across harmonic layers — not a filter. The OVERTONE SCAN steps a spotlight through individual partials with triangle, saw or random patterns, and can visit only partials in the active scale. The HARMONIC GATE reinforces partials whose pitch class matches your chord and suppresses the rest: capture a chord, follow MIDI, split the keyboard, or pick the notes on the gate's own keys. SCULPT draws the level and pan of every partial, slides the curve up the grid as a formant, and locks partials in place while the rest moves. THE HARMONIC VOCODER Pass live input or a sample through the synth as an effect. Your sound travels through a bank of tuned peaking bells rather than being replaced by filtered noise: open the Air and the source stays dry, tighten it and the bands resonate into it. Key Track is the mode switch: on it plays as an instrument, off it is a fixed filter you can sweep. Aimed at a sample, the bands track that sample's spectrum as it evolves. One level-matched Blend control crossfades it against the oscillators. PULSE-WIDTH MODULATION Set the core to a saw and Source 2 to a saw: the two ramps subtract, which is what a pulse wave is, and the phase between them sets the duty cycle. Modulate it and you have PWM. A preset in the Utility folder is ready to play. MODULATION A cog on almost every control, so the synth's own engine can drive nearly anything in the interface, including the display. Sources include velocity, envelopes, LFOs, how many notes you hold, how many oscillators sound, the synth's own output level, and Atmo, a shape driven by 84 years of barometric weather data from the Beat Kitchen Weather Sonification Project. Rates run from audio rate down to cycles that span years. THE SCOPE A stereoscope, oscilloscope, spectrum and a live per-partial display. Glow takes the trace from a hard line to a diffuse bloom, Colour sets the hue, Trace Speed and Dot set how it draws — and every one is a modulation target. Route velocity to Colour and the trace shifts as you play. LIVE INPUT A headphone button passes the side-chain straight to the output, so you can hear and see your input with nothing held: green when signal arrives, amber when a bus is connected but silent, red when nothing is. Resynth Speed locks a sample's playback speed to pitch, tape-style, or keeps them independent. Every control has a tooltip, presets work offline, and a harmony wheel follows what you play. One purchase, every update. Made by Beat Kitchen, a music production and teaching community.

About

Rithmatic

This app is an FM synthesizer featuring a vast library of classic voices. It allows users to explore, learn, build, and blend sounds using an intuitive interface and an AUv3 plugin for DAWs. It offers a comprehensive synthesis engine and various playback options.

Highlights
  • 36,118 classic DX7 voices included
  • AUv3 plugin for DAWs
  • Patch Builder to learn FM synthesis
  • Sound blending feature
  • On-screen and MIDI keyboard support
  • Arpeggiator and latch function
  • WAV export
Features
Read full description

Rithmatic is an FM synthesizer with 36,118 classic DX7 voices built in, and an AUv3 plugin for GarageBand on iPad and your DAW on the Mac. Browse them by family and by character, learn how FM works by watching it shape each one, build and blend your own, and play them from the on-screen keys or a MIDI keyboard. No account, no ads, nothing locked. IN YOUR DAW • Put it on a track in GarageBand on iPad, or in an Audio Unit host on the Mac such as Ableton Live. • Its window is the app's own Patches screen and Patch Builder, with your library. • Your bank appears as the plugin's presets, and Brightness, Attack, Decay, Release and Feedback can be automated. The patch is saved with your project. A LIBRARY THAT SHIPS FULL • 36,118 unique DX7 voices come with the app: no download, no account, no network. • Start with Essentials: the famous sounds and the songs they're on. • Browse by family, or by character: percussive, plucked, metallic, bright, sustained, swell, evolving, mellow. Or search by name. • Patch of the day: one classic voice each day, in the app and in a widget for iPhone, iPad and Mac. • 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, your Mac's keyboard, 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 under Help. 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, go full screen, or watch the output itself in the Scope look. PATCH BUILDER: 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. • 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 AND FILES • Gather patches from anywhere into your bank, then drag pads to swap or reorder them. • Export the bank as standard DX7 .syx files. Open .syx banks, or a .zip of them, from Files, Mail, AirDrop or the Finder. • 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. • 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; tips are optional and unlock nothing. Rithmatic works offline 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.

Screenshots

Beat Kitchen Harmonic Synth4 screens
Rithmatic4 screens

Verdict

The call

The clearest difference is review sentiment: Beat Kitchen Harmonic Synth at 100% against Rithmatic's 50%. Beat Kitchen Harmonic Synth also leads on rating (4.8 vs 4.0) and ratings volume (12 vs 4). Rithmatic's advantage is in-app purchases (none vs 1) and device support (4 vs 2). On price, update cadence, ads and iOS requirement there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Beat Kitchen Harmonic Synth sells 1 one-off in-app purchase. Rithmatic asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Beat Kitchen Harmonic Synth holds the better App Store score, 4.8 against 4.0. Both are backed by a comparable volume of ratings — 12 and 4 respectively. Written reviews point the same way: 100% of Beat Kitchen Harmonic Synth's written reviews are positive against 50% of Rithmatic's.

UpkeepUpdate frequency

Beat Kitchen Harmonic Synth ships an update every 3 days, Rithmatic every 2 days. The most recent releases landed on October 12, 2026 and October 13, 2026 respectively.

Scorecard6 real differences · 4 level
Beat Kitchen Harmonic Synth versus Rithmatic: the parameters behind the verdict, then further details
ParameterBeat Kitchen Harmonic SynthRithmatic
PriceFreeFree
Rating4.8 (12 ratings) — better4.0 (4 ratings)
Positive reviews100.0% of reviews — better50.0% of reviews
Number of ratings12 — better4
Update frequencyEvery 3 daysEvery 2 days — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPadiPhone, iPad, iPod, Mac — better
Requires iOS16.015.0 — better
Further details — not scored
Size60 MB64 MB
Age rating4+4+
DeveloperBeat Kitchen LLCMADE WITH BEST PRACTICE LLC

Customer experience

Beat Kitchen Harmonic Synth

All ratings12 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Rithmatic

All ratings4 ratings
Positive75.0%
Neutral0.0%
Negative25.0%
Written reviews2 reviews
Positive50.0%
Neutral0.0%
Negative50.0%

In-app purchases

1 purchases

Beat Kitchen Harmonic Synth

One-time1
  • Full Unlock$14.99
None

Rithmatic

No in-app purchases

Questions

Is Beat Kitchen Harmonic Synth free?
Beat Kitchen Harmonic Synth is free to download, with in-app purchases available.
Is Rithmatic free?
Rithmatic is free to download, with no in-app purchases.
Which has better reviews, Beat Kitchen Harmonic Synth or Rithmatic?
Beat Kitchen Harmonic Synth is rated higher. Beat Kitchen Harmonic Synth averages 4.8 out of 5 from 12 ratings, while Rithmatic averages 4.0 from 4 ratings.
Do Beat Kitchen Harmonic Synth or Rithmatic have ads?
Neither Beat Kitchen Harmonic Synth nor Rithmatic shows ads.
Which is updated more often, Beat Kitchen Harmonic Synth or Rithmatic?
Beat Kitchen Harmonic Synth ships an update every 3 days, and Rithmatic every 2 days. Most recently, Beat Kitchen Harmonic Synth was updated on October 12, 2026 and Rithmatic on October 13, 2026.

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