Another problem comes from the normalshapemediumseriesfrench.sty written by Bernard GAULLE which is the standard of the GUTenberg French association. This style changes many normalshapemediumseriesnormalshapemediumseries\catcodes which lead MusicTEX to fail in many cases. Therefore, since the version 4.99, the normalshapemediumseriesnormalshapemediumseries\catcodes of all are forced to the adequate value at normalshapemediumseriesnormalshapemediumseries\debutmorceau, normalshapemediumseriesnormalshapemediumseries\debutextrait and restored at their original value at normalshapemediumseriesnormalshapemediumseries\finmorceau, normalshapemediumseriesnormalshapemediumseries\suspmorceau and normalshapemediumseriesnormalshapemediumseries\finextrait. This means that some facilities like the guillemets or the tabulation character are inhibited within music scores (possible problem with sophisticated lyrics) but perfectly available within the normal text.
Anyway, in case of emergency, one can invoke normalshapemediumseriesnormalshapemediumseries\catcodesmusic to establish the normalshapemediumseriesnormalshapemediumseries\catcodes at their value fit for music, and normalshapemediumseriesnormalshapemediumseries\endcatcodesmusic to reset them at their external value, for example those chosen by normalshapemediumseriesfrench.sty.