What were some of the purposes of song and music in Shakespeare's plays?
Surprisingly, more than half of Shakespeare’s plays call for a song somewhere in the action. Because play performance was a public affair, the appeal of live music turned the performances into variety shows; troubadors were street performers and Shakespeare used them as characters. Usually the songs were part of the entertainment in the mise-en-scene—at court or at a wedding or festival occasion. Other times, Shakespeare inserted songs, especially lyrics, as clues in the plot. A famous example is in Merchant of Venice (III, ii) when Portia sings as Bassanio decides which casket to choose: “Tell where is fashion bred, / Or in the heart or in the head?” Portia is giving Bassanio a hint, because the lead casket (rhymes with “bred” and “head”) is the right pick. While the music is seldom preserved, Shakespeare used common folk song tunes, inserting his own lyrics.