A tonic drone holds underneath. One note of the major scale sounds above it: pick which degree it was. 7 rounds.

What Heartonic trains

Heartonic trains tonal function: the sense of where a note sits inside a key. Most ear training starts with intervals, which measure the distance from one note to the next. Tonal function is a different measurement. It asks what a note is doing relative to a home pitch, and it is the sense that lets a singer walk into a phrase they have never seen and land on the right note. The drone supplies the home pitch continuously, so nothing here depends on remembering a reference from a few seconds ago. The key is simply present, and every note you hear is coloured by it.

How to play

A quiet drone holds the tonic, sounded as the note itself plus the octave above it. Press Play the note over the drone and one degree of the major scale sounds on top. Replay it as often as you like. Then tap one of the seven pads, numbered 1 to 7 and labelled with the movable-do syllables, to say which degree you heard. There are 7 rounds and one answer per round. The drone stays on the same tonic all day, so the key never shifts under you.

The drone has its own volume control and a mute button, both reachable by keyboard. Some ears want the drone loud enough to feel; others need it far back so the target note stays clear. If a degree refuses to resolve, try lowering the drone rather than raising your effort. Muting it turns the round into a harder task, closer to naming a note from memory, which is a reasonable way to test yourself once the easier version feels routine.

How the rounds get harder

The seven rounds widen the pool of degrees you might hear, and they widen it in a specific order: 1, 5, 3, 4, 6, 2, 7. That is the stability order of the major key measured by probe-tone experiments, in which listeners rate how well each pitch fits after a key has been established. The tonic rates highest, the dominant and mediant follow, and the leading note rates lowest of the seven. Round one draws from the three most stable degrees, and each round after that adds the next degree in the list until all seven are in play. So the ramp is not a guess about what feels hard; it follows a measured ordering. The target is drawn fresh each round, so knowing the ramp does not tell you the answer.

How scoring works

Your score is how many of the seven rounds you name correctly. Get one wrong and the correct pad is highlighted and its note replayed over the drone before you continue, so a miss still teaches you the sound you missed. Get it right and the game moves straight on. Five correct out of seven earns the day towards your streak. The same daily puzzle is served to everyone, so the comparison that matters is against your own previous days.

What your score means

Read the number as a band, not a verdict:

Outcome	Rough interpretation
7 of 7	The restless degrees are landing as reliably as the stable ones
5 or 6 of 7	Solid tonal orientation; earns the day
4 or fewer	The stable degrees are anchoring; 2, 6 and 7 still need work

Confusing degree 2 with degree 7 is the single most common pattern, and it is not carelessness. Both lean towards the tonic, one from just above and one from just below, and the pull feels similar before the direction becomes obvious.

Common mistakes

The first mistake is measuring instead of listening: counting steps up from the drone rather than letting the note settle into its place. Counting works for a second or two and then collapses under time pressure. The second is ignoring the pull. Degree 7 wants to rise, degree 4 wants to fall, and those tendencies identify them faster than any interval calculation. The third is answering on the first hearing when the drone has not yet established the key in your ear; give it a second or two before the note arrives. The fourth is drowning the target by leaving the drone too loud, which is exactly what the volume control is for. The fifth is treating an octave displacement as a different degree: the same degree an octave higher is still that degree.

Practice progression

(5 min, beginner) Play the daily rounds and sing each degree back before you tap. Singing commits you, and the commitment is what turns a guess into a memory. (10 min, intermediate) Use the practice tab to run more rounds, and drop the drone volume by a step each session. (weekly) Pair it with Hearspan, which trains interval size without a key, and read the guides on movable do versus fixed do and sight-singing methods so the syllables on the pads start carrying meaning.

The science behind it

The probe-tone method underlies the ramp used here. A listener hears a short passage that establishes a key, then a single probe pitch, and rates how well the probe fits. Averaged across listeners, the ratings form a stable profile in which the tonic rates highest, the dominant and mediant follow, the remaining diatonic degrees sit lower, and pitches outside the scale rate lowest of all. The profile is a property of listeners, not of notation: people with no formal training show it too, which is what you would expect from a sense built by exposure rather than instruction. Heartonic uses the ordering, not the numbers, and it uses it for one purpose only: deciding which degrees may appear in which round. See also our guides on what pitch is and modes by ear.

Limitations

Heartonic is a game and an informal self-check, not a clinical or diagnostic tool. It uses one timbre, plain sine tones, and one scale, the major scale, so it says nothing about how you would fare with a real instrument or in a minor key. Browser audio and headphones differ, and a drone that sits comfortably on one device can mask the target on another. Seven rounds is a small sample, and a low score on a given day may say more about the room than about your ear. The stability ordering it borrows describes averages across listeners, not a ranking of any individual's ability.

Where it shows up

Hearing where a note sits in a key is what makes music learnable by ear. A choir member handed an unfamiliar part reads the shape of the line and hears each note as a function, which is why a good sight-singer can enter on the right pitch without a piano. A folk musician joining a session finds the key in a bar or two and then plays lines that fit, without knowing the tune, because the degrees behave the same way in every key. A guitarist working out a song by ear rarely counts semitones: they hear a phrase resolve and know it has arrived home. A bass player deciding what to play under a chord is choosing between functions, not frequencies. Teachers use the same sense in reverse, singing a wrong degree deliberately so a class hears the tension before it is explained. Outside performance it shows up as the ability to tell that a melody has ended rather than paused, which is the tonic doing its job. That single judgement, made without any analysis, is the thing this game isolates.

Ready to hear the key? Seven rounds, one tap each, about two minutes.

Play today's Heartonic ↑

Frequently asked questions

Do I need to read music or know solfege?

No. The pads are numbered 1 to 7, and the syllables underneath are there for players who already use them. You can play the whole game on the numbers alone.

Why is there a drone at all?

Because a scale degree only exists relative to a key. Without a continuous tonic there is no key, and the question would have no answer. The drone removes memory from the task and leaves only the tonal judgement.

Can I turn the drone off?

Yes, and you can also set its volume. Muting it makes the task considerably harder, since you then have to hold the tonic in memory yourself. It is a useful way to raise the difficulty once the normal version feels easy.

Is the key the same every day?

No. The tonic is drawn fresh each day and stays fixed for all seven rounds of that day, so you never have to re-orient mid-game but you never memorise absolute pitches either.

Why do the early rounds feel so much easier?

They draw from the most stable degrees only. Later rounds add the restless ones, so the pool of possible answers grows from three to all seven.

Heartonic

About Heartonic: hearing scale degrees in a key