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Matching a hash character (#) with a regex

I have an XML document that contains a regular expression (so you don't need to escape with \). Basically I'm trying to match musical chord symbols, and this regex works fine, but refuses to match a hash:

\b[A-G](m|b|\#|sus|\d)*?\b
Solution

  • The problem is that \b, the word boundary anchor, only matches between alphanumeric and non-alphanumeric characters, so it won't match after a # (unless that is itself followed by an alphanumeric).

    Use 

    \b[A-G](?:m|b|#|sus|\d)*(?:\b|(?<=#))

    No need to escape the #, either.

    EDIT: Changed the regex to better reproduce the intended functionality (as I think it should be)

    Currently, you're not matching some chords, though; how about

    \b[A-G](?:add|maj|j|m|-|b|#|sus|\d|°)*(?:\b|(?<=[#°-]))

    That way, you can match all of these:

    A7
Abm7 
A#m7sus4
A7b9#13
Amaj7#11
A#°
Abj7add13

    I guess there is still room for improvement, though.