Comparison

MelodySlotMachine vs SL Knock

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

SL Knock

Features
Read full description

SL Knock is a focused AUv3 dynamics and tone effect for adding punch, body and controlled low-end weight to drums, samples and loops. • Fast controls for impact and body • Tone shaping for tighter or heavier character • Mix control for parallel processing • Factory presets and local user presets • AUv3 support for compatible iPad music hosts Works as a standalone preview app and as an AUv3 effect in GarageBand, AUM, Cubasis, BeatMaker 3 and other compatible hosts.

Screenshots

MelodySlotMachine4 screens
SL Knock3 screens

Verdict

The call

The clearest difference is price: MelodySlotMachine at Free against SL Knock's $6.99. MelodySlotMachine also leads on iOS requirement (11.4 vs 15.0). On update cadence, 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; SL Knock costs $6.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly weekly. The most recent releases landed on October 15, 2026 and October 16, 2026 respectively.

Scorecard2 real differences · 7 level
MelodySlotMachine versus SL Knock: the parameters behind the verdict, then further details
ParameterMelodySlotMachineSL Knock
PriceFree — better$6.99
Rating5.0 (1 ratings) — better—
Number of ratings1 — better—
Update frequencyWeeklyWeekly
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS11.4 — better15.0
Further details — not scored
Size192 MB28 MB
Age rating4+4+
Developernewforestar co,.ltdVIACHESLAV ZHILTSOV

In-app purchases

None

MelodySlotMachine

No in-app purchases

None

SL Knock

No in-app purchases

Questions

Is MelodySlotMachine free?
MelodySlotMachine is free to download, with no in-app purchases.
Is SL Knock free?
SL Knock costs $6.99, with no in-app purchases.
Do MelodySlotMachine or SL Knock have ads?
Neither MelodySlotMachine nor SL Knock shows ads.
Which is updated more often, MelodySlotMachine or SL Knock?
MelodySlotMachine ships an update weekly, and SL Knock weekly. Most recently, MelodySlotMachine was updated on October 15, 2026 and SL Knock on October 16, 2026.

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