I feel obliged to point out that Samuel Barber died in 1981, and most of what he wrote when he was alive could easily have been written 100 years earlier. Everybody else on that list is still alive as far as I know.They're out there!
Samuel Barber - essays for orchestra
Philip Glass - violin concerto
Alan Hovhaness - Mysterious Mountain
John Adams - Short Ride in a Fast Machine (http://www.youtube.com/watch?v=LDhRQDwTDJE), Lollapalooza
John Estacio - Frenergy
Just a few examples.
Krzysztof Penderecki, arguably the world's greatest living composer was actually in town a couple of weeks ago. Didn't exactly make the cover of the Sun though. Or the Star. Did anybody hear about it other than me?