FA-81302 / Music interval and transposition theory / Member archive

Staff position and ledger lines for a clef: alto clef anchored at its middle line · case 02

Middle C in alto clef is placed on the bottom line instead of the middle line.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

Input [note, clef] where note is a letter, accidentals (# b x, ignored for placement) and a nonnegative octave, and clef is treble (bottom line E4), bass (G2), alto (F3) or tenor (D3). Position counts diatonic steps above the bottom line (lines are even positions 0..8). Ledger lines: below the staff (-position)//2 for negative positions, above (position-8)//2 for positions over 8, else 0. Return [position, ledgers] or None when invalid.

Why this case matters

Engraving and notation-rendering code places noteheads and ledger lines from pitch spellings.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
oracle 5	`[0, 0]`	`[4, 0]`	Failed

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