# PentaMonochord vs ZZZ Polyrhythm

The clearest difference is price: ZZZ Polyrhythm at Free against PentaMonochord's $1.99. ZZZ Polyrhythm also leads on update cadence (every 6 weeks vs every 24 months). PentaMonochord's advantage is in-app purchases (none vs 1) and ads (none vs shown). On device support there is nothing between them.

ZZZ Polyrhythm is free to download; PentaMonochord costs $1.99 up front. ZZZ Polyrhythm sells 1 in-app purchase, starting at $0.99 per month. PentaMonochord asks for nothing beyond the download.

PentaMonochord ships an update every 24 months, ZZZ Polyrhythm every 6 weeks. The most recent releases landed on October 16, 2026 and October 26, 2026 respectively.

## The numbers

| Metric | PentaMonochord | ZZZ Polyrhythm |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/pentamonochord/id1582880506/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 24 months | **Every 6 weeks** |
| Monetization | Paid | — |
| Size | 12 MB | 6 MB |
| Requires iOS | **12.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Lucy Hudson](https://appshunter.io/developer/1179157812) | [SMOLT STAGE, K.K.](https://appshunter.io/developer/1708601451) |

## What reviewers say

### PentaMonochord

[App page](https://appshunter.io/ios/app/pentamonochord/id1582880506)

Explore the relationship between pitch and string length with a digital monochord. Build scales, hear intervals, and learn about Pythagorean music theory through interactive blocks and historical context.

**Highlights:** Build two-octave G pentatonic scales, Hear and see interval relationships, View Hertz frequencies and string lengths, Play pentatonic tunes, Scale-building game mode, Background information on monochord system, Historical timeline

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### ZZZ Polyrhythm

[App page](https://appshunter.io/ios/app/zzz-polyrhythm/id6773375285)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| ZZZ Polyrhythm Premium | $0.99 | per month |


## Frequently asked questions

### Is PentaMonochord free?

PentaMonochord costs $1.99, with no in-app purchases.

### Is ZZZ Polyrhythm free?

ZZZ Polyrhythm is free to download, with in-app purchases available.

### Do PentaMonochord or ZZZ Polyrhythm have ads?

ZZZ Polyrhythm shows ads; PentaMonochord does not.

### Which is updated more often, PentaMonochord or ZZZ Polyrhythm?

PentaMonochord ships an update every 24 months, and ZZZ Polyrhythm every 6 weeks. Most recently, PentaMonochord was updated on October 16, 2026 and ZZZ Polyrhythm on October 26, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*