Perhaps it could be done. Chords have some structural meaning: chords fit in bars, which fit in lines, which fit in a sheet, a chord has a root, accidental, bass, suffix, etc. And an xml file has a tree structure. I felt like using regex to convert raw text into a tree structure, isn't the right tool for the job. Also, adding new features (for example, time-signature, chord durations) may be difficult to do with regex.