# KORG cortosia vs IMSLP

The clearest difference is price: IMSLP at Free against KORG cortosia's $9.99. IMSLP also leads on rating (4.6 vs 4.2) and update cadence (every 10 days vs every 2 months). KORG cortosia's advantage is in-app purchases (none vs 1). On ads, device support and iOS requirement there is nothing between them.

IMSLP is free to download; KORG cortosia costs $9.99 up front. IMSLP sells 1 in-app purchase, starting at $3.99 per month. KORG cortosia asks for nothing beyond the download.

IMSLP holds the better App Store score, 4.6 against 4.2. That said, the two scores are not equally well evidenced: IMSLP has 514 ratings behind it against 6, so its average is the more settled of the two. Written reviews point the same way: 48% of KORG cortosia's written reviews are positive against 70% of IMSLP's.

KORG cortosia ships an update every 2 months, IMSLP every 10 days. The most recent releases landed on October 30, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | KORG cortosia | IMSLP |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | [4.2 (6 ratings)](https://appshunter.io/ios/app/korg-cortosia/id952982019/reviews) | **[4.6 (514 ratings)](https://appshunter.io/ios/app/imslp/id1373671782/reviews)** |
| Number of ratings | 6 | **514** |
| Positive reviews | 47.8% of reviews | **70.1% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 10 days** |
| Monetization | Paid | **Freemium** |
| Size | 35 MB | 232 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 12+ | 4+ |
| Developer | [KORG INC.](https://appshunter.io/developer/363714046) | [Project Petrucci LLC](https://appshunter.io/developer/1373671781) |

## What reviewers say

### KORG cortosia

[App page](https://appshunter.io/ios/app/korg-cortosia/id952982019)

This app helps musicians improve their sound quality by analyzing five key elements of performance in real-time. It provides instant feedback, tracks daily progress, and allows users to compare their skills globally. Ideal for beginners and intermediate players seeking to refine their technique.

**Highlights:** Real-time analysis of five 'good sound' elements, Instant scoring on a 100-point scale, Daily practice recording and progress tracking, Global ranking for 'good sound' competition, Supports multiple wind and string instruments, Model tone comparison

**In-app purchases:** none


### IMSLP

[App page](https://appshunter.io/ios/app/imslp/id1373671782)

Access a vast digital library of classical music scores on your iOS device. Enjoy full access to commercial recordings, instant downloads, and new uploads with a membership subscription. Support the music community while exploring a comprehensive collection.

**Highlights:** Browse IMSLP/Petrucci Music Library, View musical scores, Access commercial recordings, Instant downloads, Access new uploads instantly, Membership subscription benefits

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Membership Subscription | $3.99 | per month |

**What reviewers like**

- 🚀 Integrated IMSLP library
- 👍 Well-made app
- 👍 Game changer for musicians
- 👍 Indispensable for professionals and amateurs
- 👍 Fantastic offering

**What reviewers complain about**

- 🐛 Crashes when zooming in and annotating
- 💰 Money grabbing with constant subscription prompts
- 🐛 Frequent crashes and freezes
- 🐛 Annotation issues and lost data
- 🐛 Battery drain on iPad

**Reported bugs**

- Crashes when opening scores
- Scores disappearing from library
- Login issues and lost data
- Incompatibility with older devices after updates
- Annotation issues causing loss of data

**Requested features**

- Predictive text for score annotations
- Ability to restore original zoom settings
- Metric to indicate device performance during page turns
- Folder-like organization system
- Color wheel and custom pen/highlighter options


## Frequently asked questions

### Is KORG cortosia free?

KORG cortosia costs $9.99, with no in-app purchases.

### Is IMSLP free?

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

### Which has better reviews, KORG cortosia or IMSLP?

IMSLP is rated higher. KORG cortosia averages 4.2 out of 5 from 6 ratings, while IMSLP averages 4.6 from 514 ratings.

### Do KORG cortosia or IMSLP have ads?

Neither KORG cortosia nor IMSLP shows ads.

### Which is updated more often, KORG cortosia or IMSLP?

KORG cortosia ships an update every 2 months, and IMSLP every 10 days. Most recently, KORG cortosia was updated on October 30, 2026 and IMSLP on October 29, 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.*