Here is an interesting document to share with any potential music majors that you may be teaching.  Berklee has just released a really interesting PDF titled "Salary Ranges For US Music Positions", that explores just how much musicians make on average in a given year.  It is separated out by dozens of different positions and skill levels.  

Among other things the document points out that the median salary range for US public school teachers is between $43,000 and $48,000.  The real money to be made in music appears to be in the media industries (go figure) where music is mixed with high tech computer programming skills in jobs such as video game music designer (up to $140,000 a year).   Of course at the top of the list are movie composers making up to $500,000 per film (probably more if your name ends in Williams).