For 10 points, identify this name shared by the composer of Nixon in China and a character from 1776 who is the subject of the song "Sit Down, John."
An opera by a composer with this name contains the "Chorus of Exiled Palestinians" and the murder of the wheelchair-bound title character. In a musical, a character with this name sings "We piddle, twiddle, and resolve / Not one damn thing do we solve." That character with this name sings "I say vote yes" and "Vote for independency" in a song in which others repeat "Someone oughta open up a window." The composer with this name also wrote an opera in which a U.S. president visits an Asian country and Chairman Mao dances a foxtrot with his wife. For 10 points, identify this name shared by the composer of Nixon in China and a character from 1776 who is the subject of the song "Sit Down, John."
An opera by a composer with this name contains the "Chorus of Exiled Palestinians" and the murder of the wheelchair-bound title character.
John Adams [prompt on "John"]