# MIDI MACHINE vs ThereminAir

The clearest difference is price: MIDI MACHINE at Free against ThereminAir's $3.99. ThereminAir's advantage is in-app purchases (none vs 1). On update cadence, ads, device support and iOS requirement there is nothing between them.

MIDI MACHINE is free to download; ThereminAir costs $3.99 up front. MIDI MACHINE sells 1 one-off in-app purchase. ThereminAir asks for nothing beyond the download.

MIDI MACHINE ships an update weekly, ThereminAir every 11 days. The most recent releases landed on October 24, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | MIDI MACHINE | ThereminAir |
| --- | --- | --- |
| Price | **Free** | $3.99 |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/thereminair-theremin-synth/id6772935515/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Weekly** | Every 11 days |
| Monetization | — | Free |
| Size | 52 MB | 2 MB |
| Requires iOS | 18.6 | **17.0** |
| Devices | iPhone, iPad | **iPhone, iPad, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Niklas Koellner](https://appshunter.io/developer/1885054421) | [Tom Pardee](https://appshunter.io/developer/1882976406) |

## What reviewers say

### MIDI MACHINE

[App page](https://appshunter.io/ios/app/midi-machine/id6760569464)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| MIDI MACHINE Pro | $4.99 | one-time |


### ThereminAir

[App page](https://appshunter.io/ios/app/thereminair-theremin-synth/id6772935515)

This app transforms your Apple Watch into a unique theremin instrument. Play music through arm gestures, controlling pitch and volume without touching any buttons. Explore different modes and scales to create a variety of sounds.

**Highlights:** Gesture-based pitch and volume control, Pure mode for continuous glide, Scale modes for staying in tune, Adjustable pitch ranges and vibrato depths, Live readout of frequency and note name, Complication for instant play

**Features:** Apple Watch app

**In-app purchases:** none


## Frequently asked questions

### Is MIDI MACHINE free?

MIDI MACHINE is free to download, with in-app purchases available.

### Is ThereminAir free?

ThereminAir costs $3.99, with no in-app purchases.

### Do MIDI MACHINE or ThereminAir have ads?

Neither MIDI MACHINE nor ThereminAir shows ads.

### Which is updated more often, MIDI MACHINE or ThereminAir?

MIDI MACHINE ships an update weekly, and ThereminAir every 11 days. Most recently, MIDI MACHINE was updated on October 24, 2026 and ThereminAir on October 11, 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.*