Sing these Bach chorales in German. Tap Sing for the full trainer — mic, live pitch, and the German words under the notes.
Dev ear-QA mode (?qa=1). ▶ plays ALL FOUR VOICES. Approve = sounds right; Reject = off/unpleasant (say why if quick). Verdicts save locally; EXPORT downloads a JSON to drop into 05-STAGING/bach/verdicts/.