i'm trying to define a set of custom chords for use in jazz charts, and i would like to be able to have the numbers (7, 9, 11, 13, etc) raised above the chord name. I use Brandt-Roemer standardized chord notation, so my chords look like Cmi7, Cma9, Cdim, Cmi7b5 etc.
I've checked out the regression test, and it says to add a superscript, the number has to be preceded by \super. i've tried this in the following example, and i get an 'unknown escaped string "\super"' error: