Mich. Comp. Laws § 450.1442

Sec. 442. (1) The articles of incorporation may provide that a class or series of shares shall vote as a class or series to authorize any action, including amendment to the articles. Any voting as a class or series shall be in addition to any other vote required by this act. If voting as a class or series is provided in the articles, it shall be by the proportionate vote provided in the articles or, if a proportionate vote is not so provided, then for any action other than the election of directors, by a majority of the votes cast by the holders of shares of that class or series entitled to vote on that action. (2) If voting as a class or series is required by this act to authorize an action, the action shall be authorized by a majority of the votes cast by the holders of shares of each class or series entitled to vote on that action, unless a greater vote is required by the articles of incorporation or another section of this act. Any voting as a class or series shall be in addition to any other vote required by this act. (3) Unless otherwise provided in the articles of incorporation, abstaining from a vote or submitting a ballot marked "abstain" with respect to an action that requires authorization by a vote of a class or series is not a vote cast on that action.