Playback Mode Pages

README.md

@@ -144,7 +144,7 @@ All generated monophonic guitar material uses frets 1–12 without open strings.
 
 There are no genre presets or runtime composition. The complete arranged score is played in reading order. The source-defined form and continuous whole-arrangement measure numbering remain unchanged.
 
-All parts use two music systems per page, with a single system only when the score ends on an odd system. Lines break only between measures and share consistent staff/TAB widths. A measure that cannot fit at readable spacing fails with a diagnostic instead of being split. Tall notation is scaled uniformly to fit the two rows; guitar notation and TAB stay together and aligned. TAB displays frets and ties without duplicate rests; standard notation retains the complete rhythm. The generated `.pages/*.png` files are the same page images displayed by the product.
+Normal browsing uses two music systems per page, with a single system only when the score ends on an odd system. Playback uses overlapping pairs (1–2, 2–3, 3–4): each new active line moves to the top, revealing the next below. The final line moves to the top with an empty lower half. Measure numbers sit above their starting barlines in a clear lane; playback outlines the active measure number in the accent color. Lines break only between measures and share consistent staff/TAB widths. A measure that cannot fit at readable spacing fails with a diagnostic instead of being split. Tall notation is scaled uniformly to fit the two rows; guitar notation and TAB stay together and aligned. TAB displays frets and ties without duplicate rests; standard notation retains the complete rhythm. The generated `.pages/*.png` files are the same page images displayed by the product.
 
 Write all music in reading order: repeat bars, numbered endings, navigation jumps, and pass-specific ties are rejected. The performance arrangements, including the held Ending, remain fully written out. Chord labels use `M`, `m`, `aug`, `dim`, `sus`, and `mM7`, including explicit major triads such as `CM`. Recognized Soundslice text-only harmonies are normalized into structured chords; parenthesized chords mark optional turnarounds omitted from the final vocal pass.
 
@@ -156,7 +156,7 @@ Audio comes exclusively from supplied WAV files: `package/assets/sounds/beat1.wa
 
 Tempo choices are 60, 70, 80, 90, 100, 110, and 120 BPM. With Backing on, choices are the tempos available for every catalog song; currently that is 120 BPM. Enabling Backing selects the closest available tempo, preferring the slower choice on a tie. If no tempo is shared, Backing is unavailable. Add recordings at the other tempos and rebuild to enable them.
 
-Backing recordings include one bar of count-in, the complete arrangement including its three-bar held ending, and decay. The existing WAVs are copied unchanged. The recorded count-in plays alone. Metronome clicks stop at the start of the written Ending section; those three measures and the decay remain unclicked. Metronome-only mode supplies its own count-in, waits silently through the ending, and then stops. Pages follow the rendered audio clock through all 171 measures; the final page stays visible through the recording decay.
+Backing recordings include one bar of count-in, the complete arrangement including its three-bar held ending, and decay. The existing WAVs are copied unchanged. The recorded count-in plays alone. Metronome clicks stop at the start of the written Ending section; those three measures and the decay remain unclicked. Metronome-only mode supplies its own count-in, waits silently through the ending, and then stops. Playback line turns and measure highlighting follow the rendered audio clock through all 171 measures, including rests and ties; the final line stays visible through the recording decay. Preparation and count-in have no highlighted measure.
 
 Code style is managed by Modulus, using compact two-space formatting. Python imports modules by their full names and qualifies imported symbols; only `from __future__ import annotations` is exempt, and imports have no aliases. Run `./modulus.py format` to format C++ and Python, or `./modulus.py format --check` to check formatting and prohibited aliases. The project-local Neovim integration routes Conform formatting through the same container tools, including format on save and existing LazyVim toggles. Run configure first when the image or exported tooling needs updating. Use `tooling.editor.clang_format` for C++ overrides and `tooling.format.exclude` for project-relative exclusion globs; do not edit generated `.clang-format` files.