Chord Progression Transposer

Transpose chord-symbol text while preserving extensions, alterations, parentheses, slash bass notes, spacing, and unknown tokens.

Parsing is intentionally conservative. Token mode assumes standalone chord tokens and can transpose an isolated word “A” as the chord A. Line-safe mode preserves an entire line if any non-divider token is unknown, making it safer for prose or lyrics. Roman analysis only labels unaltered scale-degree roots and does not infer harmonic function, borrowed chords, or enharmonic intent.

Transposition

Shift method

Semitones (-24 to +24)

Output spelling

Text safety mode

Roman analysis tonic (optional)

Analysis scale

Chord progression / text

Transposed text

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Recognized chord analysis

Source token	Transposed token	Roman label

Enharmonic limitation: output uses a 12-note sharp/flat spelling table, not full key-signature voice leading. Double accidentals are parsed correctly by pitch but may simplify to an enharmonic single-accidental spelling.