FA-81152 / Music interval and transposition theory / Member archive

Written key signature for a transposing part: written key moved toward concert pitch · case 02

A Bb clarinet part (written a whole step up) for C major is given two flats instead of two sharps.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

Input [concert_fifths, written_semitones_above_concert] with concert_fifths -7..7 and an integer semitone shift. The key moves by (7 * shift) mod 12 fifths; the written signature is concert_fifths plus that move, then normalised into -5..6 by adding or subtracting 12 (so six flats is written as six sharps). Invalid input returns None.

Why this case matters

Part extraction must print a transposed key signature consistent with the transposed notes.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
oracle 0	`2`	`-2`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.