[itsme]

IMHO there's no need to complicate transposing as proposed here. There's a huge community of MobileSheets users and in the ChordPro forum that is quite happy with the transposing method as it exists. With the exception that transposing in the text editor needs to be fixed to allow modifying the (very rare in my experience) cases where specifying usage of flats or sharps at song level is not sufficient.