Note Ladder

A twelve-rung ladder, one rung per note of the octave. One rung is lit, your marker is somewhere else, and every round hands you a different step: this round you move a perfect fifth at a time, next round a major third. Up, down, land exactly on it — before the fuse empties, and in as few presses as it can be done in. The ladder wraps, so the rung above B is C again, which means going down is very often the short way up.

It runs entirely on your device: 0 network requests, works offline. No ads, no account, nothing to buy, and no betting, money or prizes of any kind.

1. Focus the board — click it, or press Tab until it is focused.
2. Read the step. Above the ladder the game names the interval it is giving you this round and how many semitones that is, for example "perfect fifth, 7". That is how far one press moves you, in both directions.
3. Climb with the arrow keys. ↑ moves up by the step, ↓ moves down by it. The two on-screen buttons do exactly the same thing for touch. Nothing else on the board moves the marker — space and enter are deliberately inert, so a stray tap cannot cost you a press.
4. Land on the lit rung exactly. Overshooting is not a near miss, it is a rung you now have to come back from — and the ladder wrapping means coming back is sometimes shorter the way you were already going.
5. Mind the press counter. Every round gives you the fewest presses the puzzle can be done in, plus two spare. Spend them all without landing and the round is over.
6. Mind the fuse. The bar under the ladder is your time. It is worked out from the puzzle in front of you — a round that needs four presses is given four presses' worth of time — and it tightens slightly with every round.
7. Three lives, ten rounds. A missed round costs a life, whether you ran out of presses or ran out of time. Finish all ten with a life left and you have won the game.

Why does stacking perfect fifths reach every note but stacking major thirds only three?

Because of what the two intervals share with the octave. Twelve semitones make an octave; a perfect fifth is 7 of them, and 7 and 12 have no common factor. So repeatedly adding 7 and wrapping at 12 lands on a new note every single time and only returns to where it started after all twelve — that sequence is the circle of fifths, and it is the reason the circle exists at all. A major third is 4 semitones, and 4 divides into 12 exactly three times, so stacking major thirds gives you C, E, G♯ and then C again, forever. Three notes, an augmented triad, and no amount of pressing will ever produce a fourth one. The general rule is that a step of n semitones reaches 12 divided by the greatest common divisor of n and 12: a semitone and a fourth and a fifth reach all twelve, a whole tone reaches six, a minor third four, a major third three. The board prints that number for you every round, so you can watch the arithmetic decide what is possible before you press anything.

Why is going down sometimes faster than going up?

Because the ladder is a circle, not a staircase. Going down a perfect fifth arrives at exactly the same rung as going up a perfect fourth — 12 minus 7 is 5 — so a target that would take eleven presses upwards takes one press downwards. This is the single most useful habit the game builds: before you press, ask which direction is short. On a wrapping ladder the answer is not the one your eye suggests, because your eye is reading a straight line and the ladder is not one.

Can a round ever be impossible?

No, and it is not checked afterwards — it cannot happen in the first place. Every round is built backwards from its answer: the game picks a step and a starting rung, then places the target a whole number of presses away along that step. A rung reached in four presses is by definition reachable in four presses. A separate solver, which never sees how the round was made, then works out the fewest presses independently, and your allowance is that number plus two. So the budget you are given is the puzzle's own difficulty rather than a designer's guess, and a round that opens already solved is arithmetically impossible rather than merely unlikely.

Is there any money, betting or in-app purchase in this?

None, and there never will be. There is no currency in the game, nothing to buy, no lives to refill for a fee, and nothing of value moving in any direction. Ten rounds and three lives is the whole economy, and the score exists only so one round can be compared with another.

Do I need to read music or know any theory to play?

Not at all. The rungs carry note letters because that is what the twelve steps of an octave are called, but you can play the entire game as arithmetic on a twelve-hour clock and never think about music once. It works the other way round too: if you do read music, the game is interval drill with a timer on it, and the reach number beside each step is a fact about harmony you may have used for years without seeing it written down.

Can I play it with a keyboard or a screen reader?

Both. The arrow keys are the primary control — there is nothing here a pointer can do that a keyboard cannot, because there is nothing to click except the two movement buttons. For a screen reader the board is spoken rather than drawn: the step and its interval name, the note you are standing on, the note you are aiming at, the presses you have left and the lives you have left, refreshed as you move. Nothing anywhere in the game is distinguished by colour alone — your marker and the target each carry their own glyph and their own label.

Does it work offline?

Yes. Once the page has loaded once, the whole game is on your device. Every round is generated locally from a seed, so no part of playing involves a server, and the network can be off the entire time.

Ten rounds, three lives, twelve rungs, and steps of one, two, three, four, five or seven semitones. The tritone is left out on purpose: six semitones divide the octave in half, so every such round would be the same single press. Targets are placed at most five presses away, which keeps a round readable at speed, and the press allowance is always the minimum plus exactly two — enough to survive one wrong guess and correct it, never enough to hunt. The fuse tightens by a tenth of a second each round down to a floor it never crosses, so round ten is faster than round one but never unplayable. And the sharps-only note names are a simplification: real notation would call some of those rungs flats depending on the key, which is a distinction this game does not model.

Melody Steps is the other game here built on intervals, but it asks you to hear them rather than count them. Clock Hands is the same wrapping arithmetic on a face of twelve you already know, and Side Step is the neighbouring reflex game — a fuse, a rule, and the cost of the wrong instinct.

Bookmark this page (Ctrl+D, or ⌘D on Mac) or install the app — it works offline the next time you need it.