Interval training is practice at naming, by ear alone, the distance in pitch between two notes (an "interval" — e.g. a perfect 5th or a major 3rd). Intervals are the foundation for hearing both melody and harmony, and the starting point of all ear training.
This page is a manual for choosing the settings. Each setting is designed around established methods from music education. For each setting that calls for a decision, we give the recommended choice, what it is for, and what it trains — with the evidence behind it. If you arrived from a "?" in the settings screen, scroll to the option you need.
Training Mode
Standard is enough to start. Use Custom only to target specific intervals, and reach for "Review When You Forget" and "Weak Point Focus" once your results accumulate.
This setting decides the policy by which intervals are chosen for you. There are four modes.
The other two — "Review When You Forget" and "Weak Point Focus" — pay off once your performance data accumulates. They work the same way across every training, so they appear inline below.
"Review When You Forget" mode (spaced repetition)
Spaced repetition means an item you have already studied comes back just as you are about to forget it. The more reliably you answer something, the longer the gap before it returns; the items you miss come back sooner. It rests on the idea that recall is more durable when you space the reviews out rather than cramming the same item back-to-back.
This mode suits you once the pool of items has grown and you start noticing that things you once knew have slipped. The app handles the scheduling automatically, so you do not have to track what needs reviewing. It rewards short, daily sessions more than occasional long ones.
When in doubt, reach for it in the "maintenance" phase, after you have worked through the items once. Use the normal mode to build the foundation when everything is new, then let spaced repetition move that knowledge into long-term memory — a comfortable two-step approach. The benefit of spacing reviews for long-term retention was synthesized at scale by Cepeda et al. (2006), and the finding that the act of retrieval itself strengthens memory comes from Roediger & Karpicke (2006).
Weak-Point Focus Mode
Weak-point focus looks at your answer history, identifies the items with the lowest accuracy, and serves those to you more often. Instead of spending time on what you already answer reliably, it concentrates practice on exactly the places you keep missing. The app picks the targets automatically from your own results.
This mode suits the stage where your overall accuracy is climbing but a specific few items still trip you up every time. Because it keeps returning to your weak spots, it feels harder — and that controlled extra effort is precisely where the learning happens (the principle of desirable difficulties). It needs enough answer history before candidates appear, so play the normal mode for a while first.
When in doubt, drop in for a few concentrated sessions whenever you plateau at a given level and feel you "keep losing the same handful of items right before it would stabilize." Once the weak spots clear, return to the normal mode to keep your overall balance. Deliberately making yourself retrieve the items you tend to miss — the "testing effect" — was shown by Roediger & Karpicke (2006) to strongly benefit later retention.
The four modes exist to concentrate practice on the intervals you currently need. The quiz format itself — recalling the answer rather than listening passively — strengthens memory more than re-listening (the testing effect). "Review When You Forget" and "Weak Point Focus" automate this using your performance data.
Ref.: Roediger & Karpicke (2006) [1]
Difficulty
When unsure, start at Beginner. Step up one level once you reliably hold 80%+ at the current one.
Sets the range of intervals you'll be asked about (shown in Standard mode). It starts from the most distinguishable intervals and widens, step by step, to the harder ones.
The fewer intervals you handle at once, the less your ear must process, and the more reliably you fix the cues for telling them apart. Securing a narrow range before widening it gets you there faster than tackling everything at once. The tiers follow cognitive-load theory: keeping processing demands low early in a new skill aids learning.
Ref.: Sweller (1988) [2]
Intervals to Practice
You usually don't need this. Once the statistics reveal "the interval I always miss," select just those two or three here and focus on them.
Lets you choose which intervals appear (shown in Custom mode). It works best when you line up just an easily confused pair — say M3 vs P4, or P4 vs P5. Select at least one.
Comparing similar intervals side by side directs attention to what differs, sharpening discrimination. Mixing similar items (interleaving) yields better long-term retention than blocking one type at a time, as shown by meta-analysis.
Ref.: Brunmair & Richter (2019) [3]
Playback Mode
Learn a new interval in Ascending, add Descending and Harmonic as you get comfortable, and finish with Random.
Decides how the two notes are sounded. The same interval can be easier or harder depending on how it's played.
The aim is to hear the interval itself without leaning on one presentation. Real music uses ascending, descending, and simultaneous forms alike. Varying how it's played stops you depending on a single cue (like an ascending "song opening") and builds the ability to hear the distance itself.
Starting Pitch (Reference Pitch)
Beginners pick "Always same pitch" (C4); switch to "Different pitches" once your discrimination is stable.
Decides how the reference note — the first note sounded, from which the interval is measured (the root) — is chosen each time. If fixed, you can set it to C4 (Middle C), E4 (Guitar string 1), or A4 (440Hz) — when unsure, the recommended C4.
The two stages exist so you can lower the load by fixing conditions early, then vary them later to approach real use. Varying the starting point (interleaving conditions) retains better than monotonous repetition, as meta-analysis shows.
Ref.: Brunmair & Richter (2019) [3]
Audio Playback Speed
Leave it on Normal. Drop to Slow only when a new interval trips you up; move to Fast once stable.
Adjusts how fast the two notes play (note length and the gap between them). Appears in the sequential Ascending/Descending modes (not Harmonic). Slow, Normal, or Fast: Slow lets you listen to each note carefully, while Fast packs more repetitions into less time.
Speed is adjustable so you can match the processing load to your stage of learning. While a new interval is unfamiliar, Slow lowers the load; once discrimination is stable, Fast trains instant judgment. Keeping the load lower early follows cognitive-load theory.
Ref.: Sweller (1988) [2]
Pace Between Questions
Use Manual advance while intervals are still new; switch to Auto advance when you want volume.
Decides how you move to the next question after answering. Manual or Auto.
Both serve the same loop — recall the answer yourself, then verify. Retrieval (the quiz format) retains far better than passive re-listening. Manual is for per-question review; Auto is for raising the number of repetitions.
Ref.: Roediger & Karpicke (2006) [1]
- Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249–255.
- Sweller, J. (1988). Cognitive load during problem solving: Effects on learning. Cognitive Science, 12(2), 257–285.
- Brunmair, M., & Richter, T. (2019). Similarity matters: A meta-analysis of interleaved learning and its moderators. Psychological Bulletin, 145(11), 1029–1052.
- Karpinski, G. S. (2000). Aural Skills Acquisition: The Development of Listening, Reading, and Performing Skills in College-Level Musicians. Oxford University Press.