Strategy. To pursue its goal, the fund normally invests at least 80% of its net assets, plus any borrowings for investment purposes, in municipal bonds that provide income exempt from federal and Massachusetts state personal income taxes. These municipal bonds include those issued by the Commonwealth of Massachusetts as well as those issued by territories and possessions of the United States and the District of Columbia and their political subdivisions, agencies and instrumentalities, or multistate agencies and authorities. The fund's investments in municipal and taxable bonds must be rated investment grade (i.e., Baa/BBB or higher) at the time of purchase or, if unrated, deemed of comparable quality by the fund's sub-adviser, Insight North America LLC (INA), an affiliate of BNY Mellon … Show more… To pursue its goal, the fund normally invests at least 80% of its net assets, plus any borrowings for investment purposes, in municipal bonds that provide income exempt from federal and Massachusetts state personal income taxes. These municipal bonds include those issued by the Commonwealth of Massachusetts as well as those issued by territories and possessions of the United States and the District of Columbia and their political subdivisions, agencies and instrumentalities, or multistate agencies and authorities. The fund's investments in municipal and taxable bonds must be rated investment grade (i.e., Baa/BBB or higher) at the time of purchase or, if unrated, deemed of comparable quality by the fund's sub-adviser, Insight North America LLC (INA), an affiliate of BNY Mellon Investment Adviser, Inc. (BNYIA). Generally, the fund's average effective portfolio maturity will be between three and ten years and the average effective duration of the fund's portfolio will not exceed eight years. Because of events affecting the bond markets and interest rate changes, the maturity and duration of the portfolio might not meet the foregoing targets at all times. The fund may invest in individual municipal and taxable bonds of any maturity or duration. A bond's maturity is the length of time until the principal must be fully repaid with interest. Average effective portfolio maturity is an average of the maturities of bonds held by the fund directly and the bonds underlying derivative instruments entered into by the fund, if any, adjusted to reflect provisions or market conditions that may cause a bond's principal to be repaid earlier than at its stated maturity. Duration is an indication of an investment's "interest rate risk," or how sensitive a bond or the fund's portfolio may be to changes in interest rates. Although the fund seeks to provide income exempt from federal and Massachusetts state income taxes, income from some of the fund's holdings may be subject to the federal alternative minimum tax. The fund's sub-adviser focuses on identifying undervalued sectors and securities. To select municipal bonds for the fund, the fund's sub-adviser uses fundamental credit analysis to estimate the relative value and attractiveness of various sectors and securities and to exploit pricing inefficiencies in the municipal bond market. The fund's sub-adviser actively trades among various sectors and securities based on their apparent relative values. The fund seeks to invest in several different sectors and may overweight a particular sector depending on each sector's relative value at a given time. The fund typically sells a security when the fund's sub-adviser believes that there has been a negative change in the credit quality of the issuer or has identified a more attractive opportunity or when the sub-adviser seeks to manage the fund's duration or tax position or to provide liquidity to meet shareholder redemptions. Show less