In August of 1989, Phantom Regiment's horn-line joined the Kansas City Symphony Orchestra for an encore performance of Wagner's "Elsa's Procession to the Cathedral"http://www.youtube.com/watch?v=Tbw3VXneGso
The orchestra's conductor had told the brass line during rehearsal to "go ahead and play loud." Heh. Whoops. Probably what was Phantom's best horn-line ever unleashed full outdoor volume in the concert hall.
The build-up takes a while, but is worth it. The orchestra is pretty much irrelevant by 5:45.