Hi all,
Though strings are valid markup objects according to the type
predicate `markup?', the parser only recognizes full_markup objects as
valid for music functions, which means it's currently impossible to
pass both strings and markups unless using Scheme.
I've posted a modest patch here,
http://codereview.appspot.com/152104/show
which allows strings to be recognized as markup, thus increasing the
flexibility of music functions which generally use strings, but might
occasionally required extra formatting provided by markup commands.