How Piano Trainer Scores Your Performance

Updated

Piano Trainer scores you by comparing the notes it hears through your microphone against the MIDI file you loaded, then showing the result on a Session Complete screen. You get an accuracy percentage plus counts of correct, missed, and wrong notes, and a Retry button to run the same piece again. This applies to Play Along mode — the mode where the app says you "play with the song and get scored on accuracy." Watch Mode and Hand Practice are for following along and isolating one hand, not for producing this score.

What the Session Complete screen shows

When a run ends, the screen reports:

Metric What it represents
Accuracy Percentage score for the session
Correct Notes you played that matched the expected notes
Missed Expected notes that were not detected
Wrong Notes detected that did not match what was expected

The page also shows a Retry button to repeat the session and a Close button to dismiss the summary. In the default state shown on the page these values read 0% accuracy, 0 correct, 0 missed, 0 wrong — the empty state before any scored run.

How the score is produced

Scoring depends on two things working together: the MIDI file as the reference, and microphone note detection as the input.

  1. Load a MIDI file. Use Load MIDI or drag and drop a .mid file anywhere on the page. The page states you load a MIDI file "to start practicing piano with real-time mic feedback."
  2. Choose Play Along mode. This is the mode described as playing with the song and getting scored on accuracy.
  3. Enable mic detection. The app "detects notes played on your piano via microphone." Use the M key or the mic control to toggle it.
  4. Play the piece. The app compares detected notes to the MIDI reference as the song plays.
  5. Read the Session Complete summary and decide whether to Retry.

Because detection runs through a microphone rather than a MIDI cable, what the app "hears" determines your counts. A note that sounds but isn't detected becomes a missed note; a note it hears that isn't in the reference becomes a wrong note.

Detection settings that affect your score

The page exposes several detection options, and your choice changes how forgiving the scoring is:

  • Detection model: Standard (instant), Basic Pitch (~80% F1), Transkun V1 (~94% F1), Transkun V2 SOTA (~98% F1), and Kong/Bytedance (~90% F1). The F1 figures are the app's own labels — higher-F1 models are presented as more accurate at recognizing notes, which generally means fewer spurious missed/wrong counts from detection error rather than from your playing.
  • Noise Cancel: None, Spectral, or DeepFilterNet3. Cleaner input helps the detector avoid counting background sound as wrong notes.
  • Tune Clarity, Speed, Release, Volume: These shape how note onsets and releases are interpreted, which in turn affects whether a played note registers as correct.
  • Sens (sensitivity): Shown on the completion screen at 0.50 by default, with a Ready state — a control over how readily input is accepted as a note.

If your counts look inflated with wrong notes, detection settings are a reasonable first suspect before assuming your playing was off.

Calibrating before you rely on the score

The page includes a tuning step: Calibrate Tuning asks you to "Play A4 on your piano (hold for 1 second)" and shows an A4 Waiting... state until it captures the pitch. Running this first aligns the detector with your instrument's actual tuning, which matters for an acoustic piano or any instrument that isn't at standard pitch. Skipping it can bias detection and therefore your accuracy figure.

Practical reading of your results

  • High missed, low wrong: the app likely isn't hearing notes you did play — check mic placement, Noise Cancel, and detection model.
  • High wrong: extra detected notes, possibly from background noise or from notes outside the reference.
  • Low accuracy across the board: re-check tuning calibration and sensitivity before changing how you practice.

The Retry button repeats the same session, so you can change one detection setting or one passage at a time and compare the resulting counts directly.

Keyboard controls during a session

The page lists: Space = Play/Pause, M = Mic, S = Sheet, Esc = Stop. Playback auto-pages and the sheet music scrolls as the piece advances, so you can follow the score while the app tracks your accuracy in the background.