The Fund seeks current income exempt from regular federal income taxes and Massachusetts personal income taxes. The secondary objective is the enhancement of portfolio value. The Fund invests in municipal securities that are exempt from federal and Massachusetts state income taxes. The Fund invests at least 80% of its managed assets in securities rated, at the time of investment, investment grade (Baa/BBB or better by S&P, Moody's, or Fitch) or, if they are unrated, are judged by the manager to be of comparable quality.