The John F. Kennedy Center for the Performing Arts in Washington said it would replace the long-maligned organ in its concert hall with a new 5,000-pipe instrument built by Casavant Frères of St-Hyacinthe, Quebec. The existing organ, which was built by Aeolian-Skinner and installed in 1972, has been criticized by performers and reviewers for its poor functioning and musical inadequacy. A 1997 renovation of the hall made the problems worse. “It was getting to the point where it was ruining performances,” said Jeff Weiler, an organ consultant hired by the Kennedy Center. The new organ will be installed starting next summer, with a 61-pipe stop incorporated from its predecessor. The instrument will cost more than $2 million, the Kennedy Center said. David M. Rubenstein, the Kennedy Center’s chairman and the managing director of the Carlyle Group, a private equity firm, is paying for the new organ and its installation.