Etudle: a daily music theory puzzle (like Wordle, but for chords and keys)

Wordle worked because the rules were simple, the puzzle was the same for everyone, and you only got one a day. The constraint did the heavy lifting — limited attempts plus shared social experience. Etudle applies the same shape to music theory practice: one puzzle a day, fifteen cards, the same prompts worldwide, and a global leaderboard for everyone who finishes.

Where most music theory practice tools assume you'll show up and design your own session — pick the qualities, pick the keys, set a timer — Etudle removes the choice. There's exactly one puzzle each day, generated deterministically from the date, identical on every device. Your job is to finish it as fast as you can.

How it works

Three rounds, five cards each. The rounds rotate across categories — chord spelling, key signatures, intervals — drawn from one of a handful of round templates. Each card has one correct answer; you keep guessing until you nail it. Time is the score. Wrong guesses cost you nothing extra beyond the seconds it takes to retry, but those seconds add up.

• Same puzzle worldwide. The card list is generated from the day's UTC date, so a player in Tokyo and a player in Los Angeles see exactly the same fifteen prompts.
• Resets at midnight UTC. New puzzle daily; you can't replay a missed day.
• One attempt per day. Once you finish, your time is locked in for the leaderboard.
• Streaks tracked locally. Show up every day, your streak grows.
• Anonymous by default. Your time goes to the leaderboard under a randomly-generated tag (#K7P9XR-style); set a display name if you want.

What's on a card

Round content varies day to day, but the categories cycle through the same five card types:

• Spell a chord — see a chord name (Cmaj7, Bbm9, F♯dim), enter the notes via tap, music staff, or piano keyboard.
• Name a chord — see the notes, identify the chord.
• Mark a key signature — see "Key of D major", mark the F♯ and C♯.
• Name a key — see the notes of a scale, name the key (the prompt tells you whether it's major or minor since the same notes belong to both).
• Find an interval — see "perfect 5th above C", name the resulting note.

Each round locks to one input mode (tap, music staff, or piano), so you don't whiplash between interfaces mid-round. Guitar fretboard input is intentionally excluded from the daily — staff and piano are more universal — but it's still available in the trainers themselves.

Why a daily-puzzle format works for music theory

Music theory rewards repetition more than mastery. Knowing the third of D major is F♯ doesn't require deep understanding — it requires having seen it enough times that the answer arrives faster than the question. A single short daily session, every day, builds that fluency more reliably than occasional long study blocks. Etudle exists to make the daily session show up on its own.

The shared-puzzle format adds a social dimension that practicing alone doesn't. You can compare your time to a friend's, share the result grid, see where you ranked on the global leaderboard. That little hit of comparison turns "I should practice today" into "I want to beat my time."

The share grid

After you finish, you can share your result as a Wordle-style colored-square grid:

Green = first try, yellow = 2 guesses, orange = 3, red = 4+. The grid texture immediately shows where you struggled — useful for spotting your own weak spots over time.

Streaks and the leaderboard

Your streak counter ticks up every day you finish. Miss a day, it resets. The leaderboard ranks today's players by time only — accuracy is enforced by the keep-guessing rule, so the only way to land high is to get every card right quickly. Anonymous players show as #TAG; players who set a display name appear as "Name #TAG".

Get faster

Etudle's fifteen cards are sampled from the same content the trainers drill. If a particular card type kept tripping you up — say, you spent a full minute on "Cmaj9 → spell" — the Chord Trainer is the place to drill that quality specifically until it's reflexive. Same goes for key signatures and intervals. The daily is the test; the trainers are the practice.