Regular expression for separate and recognize musical chords symbos when mixed with lyrics.

chord regex single line (not strict).txt

\b((?:[A-G]|vii|VII|vi|VI|v|V|iv|IV|iii|III|ii|II|i|I)[#b♯♭]?(?:m(?:i(?:n(?:or)?)?)?|\+|½?dim|º|°|⁰|◦|⸰|○|⚬|∆|Δ|△|Ø|ø|⌀|⊘|∅|au[gm]|alt|sus|dom|-|add|no|omit|[Mm]aj?|M|[#b♯♭+-]|\d+|\(|\)|\/)*(?:[A-G][#b♯♭]?)?(?:\(?drop\d\)?)?(?=\n|\s|$))

chord regex(not strict).txt

# This regular expression is for separate and recognize musical chords
# when mixed with lyrics.


# Start Limit
\b
(
    # Fundamental
    (?:[A-G]|vii|VII|vi|VI|v|V|iv|IV|iii|III|ii|II|i|I)[#b♯♭]?
    
    # Term between fundamental and bass
    (?:m(?:i(?:n(?:or)?)?)?|\+|½?dim|º|°|⁰|◦|⸰|○|⚬|∆|Δ|△|Ø|ø|⌀|⊘|∅|
    au[gm]|alt|sus|dom|-|add|no|omit|[Mm]aj?|M|[#b♯♭+-]|\d+|\(|\)|\/)*
    
    # Bass
    (?:[A-G][#b♯♭]?)?
    
    # Drop
    (?:\(?drop\d\)?)?
    
    # End Limite
    (?=\n|\s|$)
)

This regular expression compared to the other file of other gist, is not strict, it allows strange combinations.

http://rubular.com/r/TU5Pjw9xzkUJYn