Please share this suggested wording with your legal advisor.
I give to The Municipal Art Society of New York, a New York non-profit (Tax ID #135562288), or its successor, the sum of $___________________, for any purpose as The Municipal Art Society of New York deems appropriate.
I give to The Municipal Art Society of New York, a New York non-profit (Tax ID #135562288), or its successor (the real estate located at __________________ or 1000 shares of XYZ stock), for any purpose as The Municipal Art Society of New York deems appropriate.
I give to The Municipal Art Society of New York, a New York non-profit (Tax ID #135562288), or its successor, ________% of the rest of my estate, for any purpose as The Municipal Art Society of New York deems appropriate.