Comparison

MelodySlotMachine vs VAPolyLead

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

Head to head
About

MelodySlotMachine

Create new melody combinations by rearranging variations using slot dials. This AI-powered tool analyzes musical structure to generate new compositions, aiding composers in projects requiring many variations. Explore next-generation music production and consumption.

Highlights
  • Dial-based melody variation selection
  • Grid tile operation for timeline visualization
  • Melody shuffle via device shake
  • Song and part selection
  • AI-driven musical structure analysis
  • Next-generation music creation
Features
Read full description

Melody Slot Machine is an application developed by RIKEN towards the integration of music and AI. You can create new melody combinations by rearranging melody variations using slot dials. When the composer composes melody variations, the structure of the melody is analyzed using a theory of music known as generative theory of tonal music (GTTM). Even if the melody switches to another variation in the middle, the structure will not be disrupted. You can expand the possibilities of composition with Melody Slot Machine. - Dial operation By rotating the dials similar to a slot machine, you can select a melody from multiple variations. The dial scrolls to the left as the performance progresses, and the leftmost dial on the screen represents the score of the performance currently being played. - Grid tile operation The horizontal grid tiles below the dials show the dial changes throughout the song. Swipe up to expand and use the elongated grid tile. - Melody shuffle When you shake your iPhone, all the dials rotate simultaneously, similar to when you pull the lever on a slot machine and stop at a random combination. - Song selection / Part switching You can select a song by pressing the musical note button. For songs containing multiple parts, you can press the button to switch between parts. - Development history The Music Information Intelligence Team, part of the RIKEN Center for Advanced Intelligence Project, is exploring potential new ways of creating and listening to music using AI. The Melody Slot Machine is an example of next-generation music production and consumption in which AI automatically analyzes the structure of a melody and resynthesizes a new melody using the obtained structure. We aim to support composers in projects that require many variations, such as in movies and games. The app is available to the public to gauge the overall interest in such a method of music creation. We ask that users the app who are prompted to fill out a questionnaire to please submit their responses. We plan to add songs in the future. If you are interested in the app and technology, please contact us at the support URL.

About

VAPolyLead

This app offers a polyphonic synthesizer with analog-style sequencing, multiple oscillators, and a resonant low-pass and high-pass filter. It includes built-in effects, MIDI support, and can be used standalone or as an AudioUnit Extension across Apple devices.

Highlights
  • Polyphonic synthesizer
  • Analog-style step sequencer
  • Resonant low-pass and high-pass filters
  • Multiple oscillators and LFOs
  • Built-in effects (delay, chorus, reverb, etc.)
  • AudioUnit Extension (AUv3) support
  • MIDI 2.0 and Ableton Link support
Features
Read full description

VAPolyLead features 3 channel analog style step sequencer and a VCF modeled on sallen-key filter of iconic monophonic synthesizer in 1970’s. This polyphonic synthesizer consists of three oscillators, resonant low pass filter resonant high pass filter, amplifier, ADSR envelope and five LFOs. VAPolyLead operates as a stand alone or as an AudioUnit Extension (AUv3) for iPhone, iPad and Mac. Stand Alone supports Ableton Link, MIDI and audio file export. Built-in Effects include delay, chorus, flanger, reverb, eq and compressor. Project files can be saved in iCloud Drive, so that the project can be accessed from iPhone, iPad or Mac. Main Features - Polyphonic Synthesizer. - Lowpass filter modeled on -12dB per oct sallen-key filter. - 3 channel analog style step sequencer. - Maximum 8 voice polyphony. it depends on performance of the device it is running. - Built-in effects and piano roll sequencer. - Audio Export. Linear PCM format (AIFF, WAV and CAF) and compressed format (AAC) - Support Audio Unit Extension (AUv3). - Support MIDI 2.0. Support Foot Pedal. - Support Ableton Link, Bluetooth MIDI, MIDI In / Out. - Works on iPhone, iPad and Mac. Support iCloud Drive to share project files between the platforms. - Factory Preset: 128, Effects: 40 Improvements - Support MIDI Foot Pedal (CC#11, CC#64) - MIDI CC Settings are saved. It will be recovered when the app launched in the next time. - UI Color can be selected from black, navy, gray or steel. System Requirements - iOS 17.0 or later - Devices with Apple Silicon are recommended. A13 Fusion or above is highly recommended. - AudioUnit Extension (AUv3) requires host application which support AudioUnit Extension. - AudioUnit Extension is supported by Apple Logic and Apple Garage Band on iOS and macOS. For any other DAW, it depends on the application and some of them don’t support AudioUnit Extension. - Sound may be distorted if CPU of the device doesn't have enough power. If it happens reduce number of voices.

Screenshots

MelodySlotMachine4 screens
VAPolyLead4 screens

Verdict

The call

The clearest difference is price: MelodySlotMachine at Free against VAPolyLead's $14.99. MelodySlotMachine also leads on update cadence (weekly vs every 2 weeks) and iOS requirement (11.4 vs 16.6). On ads, in-app purchases and device support 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

MelodySlotMachine is free to download; VAPolyLead costs $14.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

MelodySlotMachine ships an update weekly, VAPolyLead every 2 weeks. The most recent releases landed on November 3, 2026 and November 5, 2026 respectively.

Scorecard4 real differences · 6 level
MelodySlotMachine versus VAPolyLead: the parameters behind the verdict, then further details
ParameterMelodySlotMachineVAPolyLead
PriceFree — better$14.99
Rating5.0 (1 ratings) — better—
Positive reviews—100.0% of reviews
Number of ratings1 — better—
Update frequencyWeekly — betterEvery 2 weeks
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
DevicesiPhone, iPodiPhone, iPad, Mac — better
Requires iOS11.4 — better16.6
Further details — not scored
Size192 MB17 MB
Age rating4+4+
Developernewforestar co,.ltdRyo Togawa

Customer experience

MelodySlotMachine

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

VAPolyLead

Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

MelodySlotMachine

No in-app purchases

None

VAPolyLead

No in-app purchases

Questions

Is MelodySlotMachine free?
MelodySlotMachine is free to download, with no in-app purchases.
Is VAPolyLead free?
VAPolyLead costs $14.99, with no in-app purchases.
Do MelodySlotMachine or VAPolyLead have ads?
Neither MelodySlotMachine nor VAPolyLead shows ads.
Which is updated more often, MelodySlotMachine or VAPolyLead?
MelodySlotMachine ships an update weekly, and VAPolyLead every 2 weeks. Most recently, MelodySlotMachine was updated on November 3, 2026 and VAPolyLead on November 5, 2026.

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