Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 156B, § 8

(a) Whenever, with respect to any action to be taken by the stockholders of a corporation, the articles of organization or by-laws require the vote or concurrence of the holders of all of the shares, or of any class or series thereof, or a greater proportion thereof than required by this chapter with respect to such action, the provisions of the articles of organization or by-laws shall control.

(b) Whenever, with respect to any action to be taken by the stockholders of a corporation as to which a vote of each class of stock outstanding and entitled to vote thereon is required by this chapter, the articles of organization or by-laws provide that two or more classes of stock shall vote as a single class, the provisions of the articles of organization or by-laws shall control, provided, however, that no such provision shall deprive any class or series of stock whose rights would be adversely affected by such action of any right to a separate vote which such class or series may have under section seventy-one or section seventy-four.