  The musical science behind the burgeoning subgenre of post-
rock   • Photo: JSN Photography/WireImage.com   • Photo: Roger
Kisby/Getty Images   • Photo: Tim Mosenfelder/Getty Images
Explosions In The Sky   • Photo: Ilya S. Savenok/Getty Images
Godspeed You! Black Emperor May 10, 2013 -- 2:44 pm PDT By Bruce
Britt / GRAMMY.com  Over the past two decades, a curious musical
insurgency has raged on the outermost fringes of the
international music scene. Dubbed "post-rock," this burgeoning
movement was pioneered by ambitious bands who largely discarded
vocals and traditional verse-chorus structures in favor of
euphoria-inducing song cycles. Now, eccentric outliers such as
Canada's Godspeed You! Black Emperor, Scotland's Mogwai,
Iceland's Sigur Rós, and Chicago-based Tortoise are increasingly
being recognized as rock visionaries.  Having paid their dues
performing in more intimate venues, many post-rock artists are
now performing at international music festivals such as
Coachella in Indio, Calif., Glastonb