Luthia: String Tuning Puzzle

A luthier's bench, steel strings between brass pins and a chord to bring in tune. Drag the brass slider of each string to make it longer or shorter: the note changes, just as on a monochord. Luthia is played by ear. When a string is close to the right note it throbs against the drone in waves called beats, which you hear and also see on the string. The closer you get, the slower they pulse, until the string rings still and clean. • 20 levels in four suites of five: Dawn (octaves and fifths), Tide (major chords), Glass (four strings) and Nocturne (minor and seventh chords) • The top string is the drone, fixed in place: every other string is tuned against it • Strings that slant or bend around brass pivots: their length is the sum of their segments, so the right spot cannot be read by eye • Vernier sliders: slow movements fine-tune, quick movements follow your finger • Tap a string to pluck it and hear it again • A needle tuner follows the string you touch, and a lamp for each string tells you flat, sharp or in tune • The Harmony gauge shows how close the whole chord is • Every chord shows the length ratios to aim for, such as 4/5 and 2/3 • Up to three note heads per level: all three if you tune it on your own • Undo as often as you like. Need a hand? An optional video marks where to stop on one string, or turns on the precise tuner in cents for the level • When a suite is complete it becomes a spinning record: listen to its five chords again, with the note heads and time of each level • Note names as musicians say them in your language, such as C D E or Do Re Mi • Plucked-string sounds and wood-and-brass graphics, all generated by code • Headphones recommended: the beats are easier to hear Dawn, Tide and Glass are included and unlock in order. Nocturne is an optional purchase. There is a banner in the menu and at most one ad at the end of a suite, never while you tune; an optional purchase removes them. The precise tuner can also be kept for good with an optional purchase.