[Disclaimer - this response is a bit cheeky, but it may help save you some frustration down the line...] Hi David Do you have a concrete need for MusicXML? e.g. is it the only export format your preferred music program (Sibelius or whatever) supports? If you don't, but you are thinking about MusicXML because it looks like a "standard" you might want to reconsider. MusicXML really is a hideous format - representing notated music is though, western notated music enjoyed a thousand years of development before the invention of computers so it added many tricks that don't fit in well with syntax trees. MusicXML is a so-so attempt at a syntax representation. Personally I much prefer David Huron's Humdrum which represents just enough information for the task in hand, and it is a "meta-format" so what you can represent is flexible (extensible). If you want to use Humdrum in Haskell you would need to write you own parser - not a difficult task as the Humdrum format is simple and uniform. Best wishes Stephen