The six-note practice engine
Remove
one note.
The tritone goes with it — and what’s left is a scale you cannot play a wrong note in.
A major scale holds exactly one tritone. Take out the 4th or the 7th, and only those two, and nothing dissonant remains. Hexatonic drills that scale in every key, in groupings of three to nine, and tells you which bar the phrase lands on.
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Theorem one
It isn’t taste.
It’s the only way.
Remove each degree of C major in turn and count the tritones left behind. Two removals — and only two — leave none.
| removed | what’s left | tritones |
|---|---|---|
| C | D E F G A B | 1 |
| D | C E F G A B | 1 |
| E | C D F G A B | 1 |
| Fthe 4th | C D E G A B | 0 |
| G | C D E F A B | 1 |
| A | C D E F G B | 1 |
| Bthe 7th | C D E F G A | 0 |
Gospel, bluegrass, Celtic, Carnatic and West African music all arrived at “drop the 4 or the 7” independently. This table is why.
Theorem five
Six perfect fourths
in a row.
Step three degrees at a time and every interval comes out a perfect fourth or fifth. Six for six. The seven-note scale cannot do it — and the note that breaks it is the note we removed.
six notes
C–GP5D–AP5E–BP5G–CP4A–DP4B–EP4
all perfect
seven notes
C–FP4D–GP4E–AP4F–BA4G–CP4A–DP4B–EP4
F–B breaks the chain
The consequence
Six beats seven.
Here is the arithmetic.
Play a scale in groups of five against 4/4 and the accent phases against the barline. The phrase resolves only when the tonic and the accent land on a downbeat together. Six shares factors with almost everything; seven shares factors with nothing.
groups of 3
groups of 4
groups of 5
groups of 6
Which makes the six-note scale, not the major scale, the right one on which to teach grouping. It is also why a room can land a cycle together: you can land a three-bar phrase in unison, and you cannot land a twenty-one-bar one.
Open the resolution calculator →Inside
What you get
Every key, spelled properly
A note is a letter, an alteration and an octave — never a number. F♯ gives F♯ G♯ A♯ C♯ D♯ E♯, with no letter used twice.
Real engraving
Beams generated per beat, accents on the group starts, tuplets where they belong, and nothing crossing a barline.
Real piano
A sampled Salamander grand, scheduled against the audio clock so the notes land exactly where the notation says.
The resolution solver
A live bar-count for any combination of scale size, subdivision, grouping and range. Nothing else does this.
The Carnatic layer
Tisra, chatusra, khanda, misra and sankeerna — with the konnakol that belongs to each.
Available harmony
Four triads and three seventh-chord sets, two of which carry a second, equally correct name. Tap to flip the reading.
What this is not
It is not the first app to mention hexatonic scales. An iOS app called Hexatonics has existed since 2025, and mDecks’ Tessitura Pro has taught bi-triadic hexatonics since 2017. What appears to be genuinely new is the rhythm side — no tool anywhere generates melodic patterns in Carnatic groupings and reports the bar they resolve on. That is the part worth having, and it is the part this was built for.
Get your instrument.
Pick a key, pick a grouping, and play until it lands on the one.
Start practising