David Richard Campbell (born February 7, 1948) is an arranger, composer and conductor.
He has worked on over 450 gold and platinum albums including Death Magnetic (Metallica), Minutes to Midnight (Linkin Park), The 2nd Law (Muse), Spirit (Leona Lewis), These Days (Bon Jovi), Fallen (Evanescence).

 

Source: Wikipedia

Official site : http://davidmusic.com/