Muzak

the innerworkings of metal share a lot in common with classical. The riff, they would call it "ostinato", is very common in many forms of classical. Much of metal has some symphonic elements and like I said, the very idea behind the shred solos we hear in metal are very neoclassical.

Bands that are classical influenced:

Deep Purple
Rush
99.9% of all power metal bands
most Traditional, NWOBHM, and Speed Metal bands (Iron Maiden, Judas Priest, Rage, Rainbow, Diamond Head)
Malmsteen
Necrophagist (and other similar Tech Death bands)
Symphony X
Dream Theater
Children of Bodom (and Bodom clones)
Dimmu Borgir (and similar bands)
a good portion of Black Metal (especially Bathory)
any Symphonic/Gothic Metal band

Rock; it gets a bit less obvious since it is rooted in Blues. Many prog rock bands though, from what I have heard (like King Crimson, Pink Floyd, ect) take on Classical influences and sound great.