Lyrics can be introduced in two ways. The first one consists in dedicating one instrument whose normalshapemediumseriesnormalshapemediumseries\nbporteesr is zero. Then the text of the lyrics is just inserted, note by note, by inserting it at the right position between normalshapemediumseries\notes...normalshapemediumseries\enotes. The drawback is that a four voice choir needs eight instruments which may lead to troubles if there is also an orchestra score below the voices.
Therefore, another solution consists in adjusting normalshapemediumseriesnormalshapemediumseries\interinstrument and normalshapemediumseriesnormalshapemediumseries\staffbotmarg to give more place below the song instruments2.26. Then the texts of the lyrics are indicated with the song tune instrument, using normalshapemediumseriesnormalshapemediumseries\zcharnote with a negative numeric position value.
By the way, the normalshapemediumseries\zcharnote may have a normalshapemediumseries\vbox as a second argument, and this normalshapemediumseriesnormalshapemediumseries\vbox may contain several normalshapemediumseries\hboxes describing the text of the different couplets (see example normalshapemediumseriesANGESCAO).