F9 · Keyboard topography

Spec: ../F9-topography.md · Eyes forward; hands find the keys. Full tier ladder T0–T4. Honor system by design — looking down shows up as latency anyway.

tier ladder
TOPOGRAPHY · 1/5RehearsalFP-30X · USB
D4→ E4 · G4 · C4 …
eyes up — stay in position
T0 — single notes near position. Five-finger territory; the habit being built is simply not looking down. Streams spawn at a random register every rep — no home position to camp on — and the first target's latency is reported separately as the cold-start stat.
TOPOGRAPHY · 2/5RehearsalFP-30X · USB
B♭3→ E4 · G3 · D4 …
eyes up — feel for the black-key landmarks
T1 — leaps within the octave. The two- and three-black-key groups become the braille of the keyboard.
TOPOGRAPHY · 3/5RehearsalFP-30X · USB
A♭3→ F5 · C4 · E♭2 …
Stream
7/10
Median
1.1s
Replay yours vs expected
Play the correct answer to continue
…or tap anywhere to continue
T2 — cross-keyboard leaps. Wrong-octave is the signature failure — the undershot leap logs wrongOctave + shift:leap, the same tags F6 and passage shift-hesitations feed (one weakness, visible across three families). The flow stops for reconciliation: expected A♭3 dashed vs the played A♭4; continue by playing the correct key, or tap through.
TOPOGRAPHY · 4/5RehearsalFP-30X · USB
D min→ B♭ maj · F maj …
grab it — root position, either hand
T3 — chord grabs (triads; sevenths admit later). The shape-finding half of F4, without the symbol-decoding half.
TOPOGRAPHY · speed stream · 5/5RehearsalFP-30X · USB
F♯2→ C5 · A3 · E♭4 …
T4 — speed streams. The inter-prompt interval shrinks (~1.2s here) and misses simply scroll past — pressure without punishment. Summary reports accuracy, median latency, and worst-leap latency.
staff-cue stream the composite: continuous staff→hand under travel
TOPOGRAPHY · staff stream · 3/5RehearsalFP-30X · USB
Play as they come
staff→midi stream. Targets arrive on a rolling staff — current note full-ink, next ghosted, so the eyes never drop; the composite of F2's reading and F9's finding, and the bridge to F10's passages. A single-target queue (one decision at a time), so exempt from the metric-context rule; self-paced at entry, timed feed at the speed stream. Name-cue remains the pure-topography isolate for motor-only remediation.