Yul — Gugak Tuner & Jangdan
Jeongganbo, drone tone, theory
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
All features free for the first two weeks. Tuner, jangdan and theory stay free; recording, sigimsae analysis and practice scores are a one-time purchase, no subscription.
A tuner and rhythm trainer built for Korean traditional instruments. It reads pitch in yul names (黃, 太, 仲 …), shows jangdan rhythms on a jeongganbo grid, and explains the theory behind them, all in one app.
■ Tuner
Play a note and see the nearest yul and the deviation in cents at once. Set hwangjong to the court-music standard (Eb), type any Hz, or take it from your own sound. Choose sambunsonik or equal temperament. The reference tone is a real daegeum or piri recorded by the National Gugak Center. String-by-string tuning for gayageum, geomungo, haegeum and ajaeng; fingering registers for daegeum, sogeum and piri.
■ Jangdan
Dozens of court, folk, pungmul and gut rhythms on a jeongganbo grid, played with janggu, buk, jing and kkwaenggwari samples recorded by the National Gugak Center. The current cell follows along, BPM is adjustable, and you can tap cells to make your own pattern. Chain rhythms together, such as jinyangjo → jungmori → jajinmori.
■ Theory
Illustrated articles in Korean, English and Japanese on the 12 yul and tuning, jangdan, jo and tori, sigimsae, instruments and their tuning, and how to read jeongganbo, staff notation, gueum and yuljabo. Every jangdan has an explanation card, and there is a guide to the app itself.
■ Recording, sigimsae and practice (one-time purchase)
Record yourself and listen back with the pitch curve, measure the rate and width of vibrato-like sigimsae against reference values, and keep long-tone and pitch-drill scores. Buy once, keep forever. No subscription.
■ About accuracy
Tuner and sigimsae readings depend on your microphone and room and are for reference. Try them with your own instrument during the free period before buying.
Samples: National Gugak Center, Digital Sound Sources of Korean Instruments (KOGL Type 1)
Works on iPhone, iPad and Mac.
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The developer, HYO SEOP LEE, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
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Information
- Seller
- HYO SEOP LEE
- Size
- 12 MB
- Category
- Music
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - iPad
Requires iPadOS 18.0 or later. - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 2.0 or later.
- iPhone
- Languages
English and 2 more
- English, Japanese, Korean
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Lifetime $3.99
- Copyright
- © 2026 이효섭
