*Insert symphonic prog band here*

trans siberian orchestra, even if they are know more for their christmas music then they other, they combine classical and rock as well, i love thier beethoven's last night album

You'll hear classical background music in many of the songs produced by Berry Gordy's Motown Records in the 60's and 70's, which included songs by artists such as the Supremes.

Quite a few black singers and groups who didn't record for Motown also frequently used classical background music in a good number of their songs back then.

Metallica used to base their writing on classical themes, or ideas. Kirk Hammet, their lead guitarist, was schooled in Bach.

Classical music has had powerful impact on some pop stars.
 

I'll name just two of many popular music stars in particular: Elton John and Barry Manilow. Yes, I know these guys are a bit dated for the "now" generation but here's some info that you may or may not already know about these two. Elton John was classically trained and possesses a potent piano technique. Has a sound mastery of classical elements and utilizes them quite a bit in his music.

Barry Manilow's song "Could it be Magic?" actually takes Chopin's Prelude in C minor and uses it as.....drumroll....a prelude! In fact, the entire song is based more or less on Chopin's melody.

Chopin himself called a series of disconnected musical shorts "Preludes" but they are not true Preludes as Bach's are, but instead little musical gems. Of the preludes of Chopin the F# minor is my favorite.

Of course, the older song "A Fifth of Beethoven" needs no mention, although I'm not sure what the composer would have thought of this hip/hop disco rendition, but then imitation is a form of flattery, is it not?

A few other mentions before I leave for the day.

Neil Diamond was a Jewish Cantor before he made it into popular music. He has an extensive background in the classic traditions and the metal group KISS released an DVD video of some of their music backed up by a full symphony orchestra in one of music's strangest combos. The rock-DVD is called "KISS Symphony"

I don't even need bother with the huge influence classical music has had on television, film scores, children's cartoons (especially Loony Tunes) and musical genres where you might not expect it like country, rap and what not.

Oy!

There's quite obvious classical influences with bands like Therion and the stuff some would label 'avant-garde' like Vintersorg.

I once came across this boy online who listened to nothing but classical and refused to believe that metal had anything to do with it... apparently it was 'all shouting and screaming'.

Metal in general is strongly influenced by Classical.

I think that Jazz for some theoric ideas start from classical music

and vice versa.

Sigur Ros (especially the earlier albums) has a lot of classical influence. The Polyphonic Spree too. Of course the Beatles (influenced somewhat by their classical-oboe trained producer) adding string quartet to Yesterday, baroque trumpet to Penny Lane, French horn in For No One, full orchestra to A Day In The Life, harpsichord (sound--it was really piano processed to sound like harpsichord) in All My Life, and music concrete' in Revolution #9 and Being For The Benefit Of Mr Kite, have to be the originators of classically influenced rock.