question: Which is taller The Steinway Tower or 126 Madison Avenue building, as planned?
answer: The Steinway Tower
context: Title: 550 Madison Avenue
  Passage: 550 Madison Avenue (formerly known as the Sony Tower or Sony Plaza and before that the AT&T Building), is an iconic postmodern 647 ft , 37-story highrise skyscraper located at 550 Madison Avenue in Manhattan.  Designed by Philip Johnson, it was formerly the headquarters of Sony Corporation of America.  The tower was purchased by the Olayan Group and Chelsfield for $1.4 billion in 2016.
  Title: 126 Madison Avenue
  Passage: 126 Madison Avenue (also known as 15 East 30th Street) is a proposed residential skyscraper under development by Fosun Property in NoMad, Manhattan, New York City.  The building will rise 47 stories or 730 feet, and is expected to be completed by 2018.  J.D. Carisle Development Corp. is co-developing the project with Fosun Group, and Handel Architects is designing.  The developers are planned to begin construction in the second half of 2015.
  Title: The Steinway Tower
  Passage: The Steinway Tower is a supertall residential project by developers JDS Development Group and Property Markets Group in midtown Manhattan in New York City.  Located at 111 West 57th Street, the development will be a combination of the original landmarked Steinway Building designed in 1925 by Warren & Wetmore, and a new tower addition on the adjacent site.  The building will rise to be 1438 ft .  The tower will become the most slender building in the world with a width-to-height ratio of about 1:23.
citations: The Steinway Tower 126 Madison Avenue