SARAH: Consort derives from the latin words con- together and sortem, which refers to your lot in life. 

RALPH:  To consort with someone meant to be their companion or spouse, and that’s how Tybalt means it.

SARAH: But in Shakespeare’s day, consort was confused with concert, which derived from  con-, together and certāre to perform. 

RALPH: In this sense, consort could refer to a harmony, or a group of musicians playing together.  This sense of the word evolved into our modern noun, concert.

SARAH: This is how Mercutio jokingly interprets “consort.” He’s thinking of minstrels, or traveling musicians.