Speaking of arresting openings, let's not forget the opening to Stauss'
"Also Sprach..." would have blown Haydn &Co's wigs off.

....the magical, glistening bitonal starspray that begins Shrecker's "Die
Gezeichneten" opera.

....the opening of Ligeti's Violin Concerto, that starts like a rehash of
the minimalists and then gradually moves out of phase, (you can find my
review in the archives).  The perfect balm for those who believe no more
good music can be written.  IMHO, Ligeti is the heir to Bartok.

John Smyth