Another quotation from Michael Broyles’ book Mavericks, mentioned below. The problem for conservative orchestra audiences, again, isn't the style of a new work, but the mere fact that it is new. Same as it ever was, at least since 1850.
William Schuman often told the story of a concert in Macon, Georgia, after which he was approached by a member of the audience who told him she liked his piece even though she did not generally like atonal music. Schuman tried to explain that the work indeed was not atonal, but tonal, even though the harmony may be complex. Finally she interrupted his explanation with the comment, "That's very well, Mr. Schuman, but in Macon, Georgia, your piece is atonal."